- How to Plant and Grow Bulbs
- Selecting Flower Bulbs
- Choosing a High Quality Bulb
- Buying Bulbs
- Planting Flower Bulbs
- Pointers for Planting Bulbs
- Fertilizing Bulbs
- Pest-Resistant Bulbs
- About Tender Bulbs
- How to Overwinter Tender Bulbs
- How to Plant Bulbs
- Which End of a Bulb should be Planted Up?
- Calla Lily Bulbs
- How to select & plant Calla Lily bulbs
How to Plant and Grow Bulbs
Muscari and Narcisus ‘Double Camparnelle’, a highly fragrant daffodil that perfumes the air with the scent of gardenia
This page contains information about growing and storing bulbs, corms, rhizomes, and tubers of all kinds. While the specifics of growing bulbs differs across regions, much of the information presented here will be useful to bulb growers everywhere. Information and links are continuously being added so come back often.
Topics covered include the following:
Selecting Flower Bulbs
Planting Flower Bulbs
About Tender Bulbs
Overwintering Tender Bulbs
Selecting Flower Bulbs
Bulbs generally fall into one of two categories – spring-blooming (or hardy) bulbs and summer-blooming (or tender) bulbs.
Spring-blooming bulbs are planted in the fall, overwinter under ground, and bloom in the spring. In order to bloom, they need to a cold period during the winter, so not all spring-blooming bulbs will bloom in the warmer parts of the country. Spring-blooming bulbs include well-known favorites, such as tulips, daffodils, crocuses, and grape hyacinths, as well as lesser-known bulbs, including some of my favorite smaller ones.
Summer-blooming or tender bulbs cannot survive winter in the ground in colder regions of the country. They are generally planted in the spring after the last hard frost and are dug up and stored in a cool place in the fall. For information on storing tender bulbs, click here.
When selecting spring-blooming bulbs, aim for a wide range of flowering times. Most bulbs indicate on the packaging whether they are early, mid-, or late-season bloomers. By including bulbs that flower during each of these timeframes, you can have continuous blooms in your garden for up to three months!
Early Spring (weeks 1-4)
Snowdrop (Galanthus nivalis)
Winter Aconite (Eranthis hyemalis)
Danford Iris (Iris danfordiae)
Crocus (Crocus spp.)
Glory-of-the-Snow (Chionodoxa luciliae)
Siberian Squill (Scilla siberica)
Striped Squill (Puschkinia scilloides)
Grecian Windflower (Anemone blanda)
Common Grape Hyacinth (Muscari botryoides)
Early Daffodils (Narcissus spp.)
Netted Iris (Iris reticulata)
Midspring (weeks 4-8)
Late Spring (weeks 8-12)
Choosing a High Quality Bulb
There are two things to look for when buying bulbs: size and firmness.
Bulb Size – The larger the bulb, the larger the plant and flower. You’ll generally find that bulb prices correspond to size – so, for example, a larger daffodil bulb will cost more than a smaller one.
Choose a bulb size that makes sense for you. If you’re planting a large area that will naturalize over time, you may want to consider smaller bulbs that can grow after planting. These are sometimes referred to a “landscaper” or “contractor” sized bulbs and will often cost a little less (which is ideal if you’re planting a lot of them). However, if you plan to plant a smaller number of bulbs and want them to make a big impact, then larger bulbs would be a better choice.
Also, be aware that newer introductions and bulbs that are relatively rare or difficult to propagate will cost more. For example, some of the ornamental onions (Allium) can cost over $10 per bulb!
Firmness – You want to choose bulbs that are firm and free of soft spots or visible rot. Also check for signs of disease, cracking, or indications that the roots (on the flat end of the bulb) have been seriously damaged. All of these problems are likely to cause your bulbs to rot in the ground.
I generally recommend buying bulbs online from reputable dealers (see the list of recommended vendors at the top of the sidebar to the right). You’ll have a wider choice of bulbs and they’re generally larger that the ones bought at home improvement stores, or even your local nursery or garden center. However, if you want to buy locally, I strongly recommend supporting your local nursery or garden center as they will typically have good quality bulbs and can often order something for you if it’s not in stock.
Buy bulbs that grow well in your location—don’t be tempted into buying bulbs that are best suited for the humid south or bone-dry west if you live in the northeast.
Buy in large quantities. Most bulbs look best when planted in large masses. One or two bulbs here and there won’t have any impact in your landscape.
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Planting Flower Bulbs
Planting flower bulbs is easy and will reward you with a beautiful spring show – if you do it right… Just follow these two basic rules to planting flower bulbs.
Plant Bulbs with the Pointed End Up – All bulbs have a “pointy end”, although it may not always be obvious. If you cannot tell which end is pointed, look for a flatter area where the roots are or have been – this is the bottom of the bulb. If still in doubt, just take a guess and plant the bulb. It will still grow, even if it’s upside-down, although the plant will be unnecessarily stressed and may eventually die if left upside-down. You can always dig up the bulb after it has finished flowering to see which side the leaves have emerged from (that’s the top of the bulb).
Plant Bulbs 2 – 2½ Times Deeper Than the Bulb Height – As a general rule of thumb, plant the bulb 2 – 2½ times deeper than the size of the bulb (measured from top to bottom). So if your bulb is a small 1 inch bulb (like a crocus), you would plant the bulb 2 to 2½ inches deep. If your bulb is a larger 3 inch bulb (like a daffodil), plant the bulb 6 to 7½ inches deep.
And that’s generally all there is to it. But if you want more details, read on…
In most locations, September is the perfect time to select your spring blooming bulbs. Most bulbs that bloom in the spring (e.g., tulips, daffodils, crocus, snowdrops) need to be chilled in order to bloom well. Here in southern Connecticut, plant bulbs in October and you’ll be rewarded with a colorful display starting in March.
Pointers for Planting Bulbs
- Don’t make the common mistake of planting tulips or daffodils in a straight line. Not only does it look un-natural, the flowers are often lost against the background and any bulbs that don’t emerge in spring will make a very noticeable hole in the display.
- Before planting, consider the light requirements of the bulbs and place them accordingly. Keep in mind that some bulbs will bloom before shrubs and trees leaf out.
- Plant small bulbs, such as muscari, squill, chionodoxa, winter aconite, and ipheon, in large drifts and allow them to naturalize.
- Consider some of the less common bulbs, such as the ornamental onions (I love drumstick allium), camassia, and small species tulips. Their flowers always evoke a “Wow, what’s that?!” from passers-by.
- Follow planting instructions that come with the bulbs. Some bulbs need to be planted deeper than others. As a general rule of thumb, the planting depth should be 2 to 3 times the height of the bulb (measured from the bottom of the bulb).
- Bulbs need well draining soil (they will tend to rot in clay). If necessary, amend the soil with compost before planting.
- Fertilize with a soluble 10-10-10 fertilizer (or bulb fertilizer) or incorporate superphosphate into the soil when you plant to encourage root growth.
- Do not add bonemeal or any type of bloodmeal to the planting hole. Those meals can lure animals to dig up the bulbs.
- If squirrels, voles, or other animals insist on digging up your bulbs, plant the bulbs in cages or surround them with chicken wire. The foliage will grow right through it but the animals won’t be able to feast on your tender bulbs.
- Water the bulbs well right after planting. They need to grow roots before the ground freezes solid. But don’t overwater or the bulbs will rot.
And if you’re looking for a good tool for planting bulbs, look no further than the Joseph Bentley long-handled bulb planter that we reviewed a while back.
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Many gardeners assume that because hardy bulbs come back year after year that they need no special attention. While bulbs can survive for years without fertilizer, they thrive when given this little bit of extra attention.
Fertilize Bulbs When Planting – To encourage flowering in spring, add some bulb food to the planting hole before putting your bulb in. Just make sure that there is a thin layer of dirt between the bulb and the fertilizer, so that the bulb does not get fertilizer burn.
Fertilize Bulbs When Established – Fertilize bulbs twice a year for best results – once at the beginning of spring, before the plant flowers, and again in fall, after the first frost has hit your area. Fertilizing in spring helps bulbs start to store up food for over-wintering, while fertilizing in fall helps bulbs produce better flowers in the spring.
Chemical Bulb Fertilizers – Specialized bulb fertilizers can be expensive and aren’t really necessary. The key is to choose a chemical fertilizer in which the phosphorus (P) number is the highest (e.g., 5-10-5). Phosphorus is used by bulbs to grow and multiply, as well as to produce bigger and more vibrant flowers. Other important nutrients include nitrogen (N) and potash (K). Nitrogen helps bulbs put out healthy foliage, which in turn helps them to collect more energy from the sun. Potash will help the bulb fend of disease and live longer.
Natural Bulb Fertilizers – For gardeners who prefer to use only natural materials, compost will work well as general fertilizer (and soil conditioner). However, to ensure that there is enough phosphorus available to the bulbs, you may want to consider adding some bone meal to your compost.
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Garden pests, especially deer, are a real problem for gardeners in many areas of the country. It’s a constant struggle to find plants that the deer won’t eat but that are also beautiful and/or fragrant. Fall can be especially difficult, as gardeners know that planting tulips and crocuses is simply going to a lot of effort to provide deer with a tasty spring treat. But there are some bulbs that deer generally won’t eat because of the bitter taste (unless they’re starving, in which case they’ll eat just about anything) – planting these pest-resistant bulbs can give you a beautiful spring display without attracting every deer in the neighborhood.
Below is a list of pest-resistant bulbs from the Netherlands Flower Bulb Information Center in New York City. All are ranked high on beauty and low on pest-appeal. All are hardy in USDA zones 4 – 8, depending on variety.
- Allium, ornamental onion. Blooms late spring to early summer.
- Camassia. Blooms late spring.
- Chionodoxa.glory of the snow. Blooms late winter, early spring.
- Colchicum. Blooms late summer and fall.
- Crocus tommasinianus. Blooms late winter, early spring.
- Eranthis, winter aconite. Blooms late winter, early spring.
- Fritillaria. Blooms mid to late spring, depending on variety.
- Galanthus nivalis, snowdrop. Blooms late winter, early spring.
- Hyacinthoides hispanica, Spanish bluebell. Blooms late spring.
- Hyacinthus, hyacinth. Blooms mid-spring.
- Ipheion. Blooms early- to late-spring, depending on variety.
- Leucojum, snowflake. Blooms mid- to late-spring.
- Muscari, graph hyacinth. Blooms mid- to late-spring, depending upon variety.
- Narcissus, daffodil. Blooms early- to late-spring, depending upon variety.
- Ornithogalum. Blooms early to mid-spring.
- Scilla. Blooms early spring, to early summer, depending upon variety.
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About Tender Bulbs
Tips on Storing Tender Bulbs – A good way to store bulbs and corms is to fill old nylon stockings with peat moss, vermiculite or perlite, place the corms in the stockings, and hang them up on a clothesline or a hook. This procedure allows for good air circulation.
Keeping Overwintering Tender Bulbs Cool – If you don’t have a garage or other suitable outdoor location in which to keep bulbs cool, you can still keep them cool in your unfinished basement. Place the bulbs in a box lined with plastic and cover it with another sheet of plastic. Tilt the box towards an outer wall of your basement, with the plastic ‘top’ against the concrete wall. This procedure will generally give you a cooler temperature in the box than in the rest of your basement.
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How to Overwinter Tender Bulbs
While gardeners in zones 8 and above can grow tender bulbs, corms, rhizomes and tubers year round, in other regions we need to dig and store these plants to overwinter them. There are no hard-and-fast rules for overwintering tender plants but here are some general tips:
- Use a pitchfork to lift the plants – it’s less likely to damage them.
- Keep the stored bulbs dry and cool – about 50F is cool enough to keep them dormant.
- Don’t store in air tight containers that could cause moisture, rot, or fungus to build up.
- Check regularly for desiccation and mold.
- Don’t forget to label by type and color.
Alocasia (Elephant’s Ear) – Most people treat these as potted houseplants and simply move them indoors and outdoors as weather allows. But if you grow them in the ground, lift and pot them before frost. Alocasia tubers can also be cleaned and stored in peat moss, in a cool, dry spot. Plants tend to get larger as the tubers age. Repot in early spring.
Begonias, Tuberous – Allow a light frost to kill the tops, but dig up the tubers before a hard frost freezes them. Cut back the foliage to about 6 inches and let the tubers dry for at least one week. Remove excess soil and foliage and store in peat moss, sawdust, perlite or vermiculiate at 50 degrees F. Repot in early spring and keep warm (68 – 75 degrees F). Move to a sunny spot when shoots appear. Keep evenly moist, but not wet. Plant outside after all danger of frost. NOTE: Begonia tubers must be started indoors in late January or February for summer flowers.
Caladium – Lift caladium plants before frost and allow them to dry in a warm spot. Cut back the foliage after it dies. Caldium bulbs don’t like to be stored in cold temperatures. Keep at 50 – 60 degrees F. Pack loosely in peat moss. Repot in early spring, about 2 inches deep, knobby side up. Keep the soil moist and warm (about 75 – 80 degres F). Move or plant outdoors after all danger of frost.
Canna—Allow frost to kill the tops, but don’t allow the rhizomes to freeze. Carefully lift the plants and cut off the dead tops. Hose off excess soil and allow to dry.
Rhizomes can be wrapped in newspaper and stored in paper bags or cardboard boxes, at 45 to 50 degrees F.
Cannas can be divided by hand. Simply break the rhizomes apart, insuring there are at least 3 eyes per division. Repot in early spring or plant directly in the garden once the temperatures remain above 70 degrees F.
Colocasia esculenta (Taro) – Like Alocasia, Colocasia can be brought indoors as a houseplant or dug and overwintered as a tuber. Store the dried tubers in peat moss. Check the tubers monthly and cut away any soft spots that may develop. Allow the remaining healthy portion to dry before restoring in peat. Colocasia can be repotted about 8 weeks before the last expected spring frost. If dividing, be sure each tuber piece has an eye. Allow the tubers to dry a few days before replanting them.
Crocosmia, Freesia, and Gladioli—Tubers are usually brought inside in mid-fall. Lift the plantswhen they yellow or after thefirst frost, allowing some soil to cling to them. Cut the stems back to 1 inch and allow corms to dry thoroughly for a couple of weeks. At this point, the remaining soil on the tubers should break away easily. Remove any old, shriveled portions, keeping only the new plump corms.
Once the corms have dried thoroughly, some people choose to dust them with a fungicide before storing them.
Store corms in peat moss, vermiculite or perlite at temperatures of 40–50° F.
In spring, plant the corms directly in the ground when the ground warms. Stagger plantings to extend the season of bloom.
Dahlia—Because these tubers don’t store very well, it is best to wait until the beginning of November (late fall) before bringing them inside.
Dahlias can be over-wintered in the ground as far north as zone 6 with sufficient mulch, but it’s risky. If you can, it’s better to lift them at the end of the season.
At the first light frost, cut back foliage to about 6 inches (or allow it to die back) and then leave the plant in the ground for a week or so (dig up the dahlia tubers if a hard freeze is predicted – don’t let them freeze in the ground). It’s easiest to see the dahlia eyes, for division purposes, about a week after the tops are cut or killed back.
Overwinter in peat moss at 50F to prevent premature sprouting and/or rotting. These tubers don’t like to get completely dried out. Check monthly for dehydration and mist lightly, if necessary.
In the spring, dahlia tubers are usually direct planted in the garden, once temperatures warm.
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Color combinations are always a matter of personal taste. One often-overlooked detail, however, is to remember the color of the house. Be wary of any colors that might clash with its exterior. Too often, what looked splendid in the catalogue leaps to life in the spring at war with the colors of the backdrop. Too late, nothing can be done.
On bulb quantity, again it is better to err on the side of too many than too few. A general rule to follow for tulips is to have at least eight bulbs per foot, maybe even 10 or 12. And if the bulbs are set in a border, try to set them in a circle of at least seven, no less than five.
Depth is important, too. There are bulb planters for sale that make the task easier. For those who trust their own instincts, a good rule to follow is to set each bulb as deep as the trowel. For those who have extremely sandy soil, a bit deeper is better.
Fertilizer should not be needed at planting time unless the soil is of very poor quality. Each bulb is a self-contained package, already complete, with bloom and leaves just waiting for moisture and warmth to spur its flowering.
Fertilizer will be needed in spring, however. When the tops of the foliage start to appear above ground, then a sprinkling of, say, 5-10-5 can be scattered over the plantings, especially of daffodils and other so-called permanent bulbs. This nutrient supply will nourish the development of the new flower buds and leaves, which will be forming for the following spring. Just when the bulb is putting out its all for the spring display, nature is already making plans for the future underground.
When setting out some of the large bulbs, like those of the giant alliums or the many forms of fritillarias, individual planting holes are usually necessary. These can be situated to show themselves off nicely in the confines of a flower border. But again, one bulb usually doesn’t do the trick. Plant these larger, more expensive, bulbs in groups of at least three.
The simple efforts of bulb-planting bring bountiful rewards. Even the simplest planting can change a drab spring scene into a delight.
How to Plant Bulbs
By Steven A. Frowine, The National Gardening Association
Planting bulbs is simple. But before you start the planting process, be sure the chosen spot has good, well-draining soil. Bulbs rot in soggy ground and struggle in sandy soil; although adding some organic matter can ease these problems considerably, it is still in your best interest to select a location that resembles an ideal environment for your bulbs.
Learn how to plant bulbs for the best results with these steps:
Dig an appropriately sized hole.
If you’re planting only a few bulbs or you’re spot-planting (tucking bulbs in among other plants in a mixed bed), use a trowel. If you’re planting lots of bulbs, break out the shovel and make a trench.
Not all bulbs are the same size, so not all bulbs should be planted the same depth. The general rule is three times as deep as the bulb‘s height. This guideline varies a bit based on your soil type. In sandier soils, you can plant a little deeper; in heavy clay soils, a little shallower. If you forget how deep to plant your bulbs, consult the supplier’s label or catalog. Too shallow, and your bulbs may poke their heads above the soil surface too early and get damaged by wintry weather; too deep, and they’ll take longer to emerge.
Roots grow out of the bottom of the bulb, so the quality of the soil underneath it is more important than what you pack the hole with. If you’re amending the soil with organic material like compost or sphagnum moss, dig somewhat deeper-than-recommended holes so you can accommodate this addition.
Distance apart varies with the type of bulb and the sort of display you have in mind. If you crowd the bulbs underground, the eventual show may suffer. Certainly, don’t let the bulbs touch one another. The general rule is at least three bulb-widths apart “on center“ (from the center of one bulb to the center of the next). But experience can tell you what the bulbs you’ve chosen tolerate and how dense you like your displays.
Add a fertilizer.
Use a fertilizer that has a higher phosphorus number, such as a 5-10-5 fertilizer. Phosphorus (the P in the N-P-K on fertilizer labels) is important for the root growth as well as flower production. Just sprinkle the fertilizer in the bottom of the hole and scratch it in so it mixes with the soil a bit.
If the ground is bone dry, water a day or so before planting so the ground is damp but not muddy when you’re planting the bulbs. If you want to wait to fertilize, you can scratch the fertilizer into the surface of the soil in the spring as the bulbs are growing.
You want the nose, or growing point, to point up and the roots, or basal plate from which they’ll grow, to point down. (If you can’t tell, plant the bulb on its side — the plant will figure it out in due course! Botanists call this nifty skill gravitropism.) Make sure the bottom of the bulb is in contact with soil; if you leave an air pocket, the roots can dry out and the bulb won’t grow or won’t grow very well.
Backfill with soil and water generously.
As you scoop soil back into the hole, firmly press it in place to prevent air pockets. Water well (some settling will occur) and then add a bit more soil as needed.
Indicate where you’ve planted your bulbs so you don’t plant other flowers in the same place. Mark the locations with permanent nonrusting, nonrotting labels like those made of zinc or copper.
Which End of a Bulb should be Planted Up?
Which End is Up?
One of the most popular questions asked by beginners to bulb gardening is, “How do I know which end of the bulb to plant up?” While the answer to this question can vary based on the type of bulb, generally speaking, the pointed end of the bulb should be planted up (such as with a tulip, daffodil, or hyacinth). Also, if a bulb is smaller than the size of a nickel, there really isn’t a top and bottom.
The good news is that bulbs are quite smart and they’ll figure out which direction to grow, regardless of how they are planted! If a bulb is planted upside down, it will simply take an extra day or two to reach the surface. If after deliberating over which end is the top and you still can’t tell, plant the bulb on its side. Once again, the bulb is smart enough to know which way to grow and will now only have to travel half the distance to the surface.
A few bulbs, especially some of those bulbs planted in spring, have a more definite answer to the question. For instance, begonia tubers have a concave and convex side. In this case, the “hollow” side of tuber should be planted down and the “rounded” side up. Other tuberous spring planted bulbs such as cannas and callas grow long and narrow. These should be planted horizontally 1″ or 2″ below the ground’s surface.
The smooth side of the Elephant Ear bulb is the top and should planted up.
Perhaps one of the most confusing bulbs to know which direction to plant is the Elephant Ear. As those of you who have previously planted one know, an Elephant Ear bulb is very round and has no definite “points”. However, most of these bulbs will have a smooth side as well as a side that contains more bumps and maybe even a few root hairs from the previous growing season. The smooth side of the Elephant Ear is typically the top and should be planted up. Chances
The bumpy side of the Elephant Ear bulb is the bottom and should be planted down.
are, the bumpy side with some possible hairs is slightly flatter than the smooth top side. This is the bottom. Like all bulbs, an Elephant Ear will know which way to grow regardless of how it is planted. When in doubt, plant it on its side! See pictures below for more clarification.
Spring is definitely here and gardeners everywhere are rejoicing! So get out in the garden and get to work! It’ll make you feel good 😉
Have a question about which way to plant your bulbs or any other gardening topic? Ask Bridget! Email her at [email protected]! If she features your question in a future post, you’ll receive a coupon for your next order with Holland Bulb Farms!
- Choose healthy bulbs. Avoid bulbs that are withered, spongy, or moldy. In general, the larger the bulb for its type, the more flowers. Small bulbs are less expensive and will have smaller or fewer flowers. If you can be patient, theses bulbs will mature in three or four years.
- Select an appropriate location. Most flowering bulbs prefer full sun, but that can be almost anywhere in the spring as the trees do not yet have their leaves. So don’t overlook a spot that seems perfect, just because it’s a bit shady in the fall. Woodland bulbs such as Anemone nemorosa (Woodland Anemone), Arisaema (Jack-in-the-Pulpit), Erythronium (Dog’s Tooth Violets), Galanthus (Snowdrops), and Trillium prefer a bit of cool shade.
- Bulbs do not like sitting in wet soil. This is especially true when they are dormant in the summer. Choose to plant in a spot that’s well-drained to prevent rotting.
- Plant bulbs as long as the soil is soft enough to dig a hole. This is true in areas with cold winters. However, they’ll have more time to begin growing roots if planted before mid-November.
- Purchase pre-chilled bulbs. If you live in an area without a freezing winter, purchase pre-chilled bulbs. You won’t have to plant these bulbs until early spring.
- Plant with the pointed side up. The pointed end is the stem. You may even be able to see some shriveled roots on the flatter side. If you really can’t tell, don’t worry about it. The stem will find it’s own way, sooner or later. You can hedge your bets and plant them sideways.
- Plant bulbs to a depth of about three times their diameter. For daffodils, that’s about six to eight inches. Smaller bulbs can be planted to a depth of three to four inches.
- Mix some bone meal or superphosphate into the soil. Put either the bone meal or superphosphate at the bottom of the hole at planting time to encourage strong root growth. You could mix in some water-soluble fertilizer as well, but it’s not necessary if you’ve already amended your soil.
- Sprinkle red pepper in the planting hole if rodents tend to eat your bulbs. A more secure method is to plant your bulbs in a cage made of hardware cloth. The roots and stems grow through, but the rodents can’t get to the bulbs. Make it easy on yourself and create a cage large enough to plant at least a dozen bulbs. Or you can make it really easy on yourself and stick to daffodils, which rodents and most other animals avoid.
- Replace the soil on top of the bulbs. Water the bulbs after planting to help them settle in and close any air pockets. Through the fall and winter, you only need to worry about watering your bulbs if you’re having a particularly dry season. Come spring, you should be well rewarded for all your efforts.
Calla Lily Bulbs
Try your hand at growing calla lily plants. These bloomers are a cinch to grow, and in areas where calla lily bulbs aren’t hardy, you can easily store bulbs for winter. To get started planting calla lily bulbs, choose a spot that’s sunny. In hotter regions, like the Deep South or Desert Southwest, choose a site that’s shaded during the hottest part of the day.
Colorful calla lily flowers (Zantedeschia hybrids) come from bulbs. Typically calla lily bulbs have one side that’s smoother than the other. The side that’s bumpy or has little circular areas produces growing shoots. You might even see calla lily eyes (growing tips) inside the circles.
How to plant calla lily bulbs isn’t difficult. Plant bulbs so the side with the growing tips faces up. If you can’t detect that side and plant your bulbs upside down, shoots will bend around bulbs and still pop out of soil. Calla lily bulbs are pretty goof-proof. The trickiest part of planting calla lily bulbs is that you must wait until soil is warm and there’s no chance of frost. Calla lilies are tropical plants that crave heat. Air temperatures should be reliably above 55°F at planting time—and beyond.
Tuck calla lily bulbs 3 to 4 inches deep into soil that’s rich in organic matter and drains well. Grow calla lily plants in containers or in-ground beds. Amend beds with organic matter if you have heavy clay soil. In containers, use a commercial bagged soil-less mix designed for pots. Soil must drain well or you risk having calla lily bulbs rot. This is also why it’s important to plant after soil warms. Calla lily bulbs plus cold, wet soil leads to bulb rot.
Mulch soil once calla lilies are up and growing to keep roots on the cool side. If you’re growing calla lilies in containers, place other pots around the calla lily pot to shade the container.
Flowers appear in summer and linger about two weeks. You can cut the blooms for bouquets, but be careful not to get the sap on your skin. After flowers fade, petals shift to darker shades or turn green and close up. This signals the plant is shifting into seed production. Cut off dead blooms to prevent seed formation and let bulbs start building food reserves for next year’s flower show.
Calla lily plants are hardy in Zones 8 to 9, although gardeners have reported hybrids surviving winters in Zone 6 in protected locations. Outside of Zones 8 and 9, lift bulbs in fall, after leaves yellow and die. In coldest zones, leaves may get frosted and die back. Do not let calla lily bulbs in pots experience a hard freeze. It could damage bulbs.
In late fall in Zones 6 and colder, dig bulbs and dry them. If stems are still attached, they should dry up and fall off. Or use a gentle tug to remove them, but allow the newly exposed spots on bulbs to dry before storing. Do not store moist bulbs; they’ll rot. Store calla lily bulbs in a cool spot for winter. Stash them in a paper bag, or store them in layers in a cardboard box.
How to select & plant Calla Lily bulbs
4 September 2017
When buying Calla Lily bulbs, be careful not to buy bulbs that are too small to flower in their first season. Patience may be a virtue, but there is nothing worse than the expectation of a flower and no flower appearing. This often causes the gardener to believe that they have no success growing Calla Lilies, where often it is the fault of the bulb being sold too small.
The photograph with this article shows the two types of bulbs. Flowering, and not flowering size. If you look closely at the flowering size bulb, you will see baby bulbs growing on the side of the large bulb. These baby bulbs will become bulbs of the not flowering size next season. Only the season after, will these bulbs be large enough to flower. Be wary when buying bulbs and make sure they are of flowering size. Yes, size does matter when it comes to some bulbs!
Plant the Calla Lily bulb, three times it’s width under the soil surface, smooth side down. Start to water when the green shoots appear above the soil surface.
Calla Lilies are clumping plants and are dormant over Winter. There is no need to remove the bulb over the Winter months.