Dahlias are an essential choice for the summer garden. The easy-to-grow tubers will produce a phenomenal display of colour in a range of styles with beautiful dense foliage. Dahlia work perfectly with almost all types of plants, and complement any garden wonderfully regardless of size.
Whether you’re looking to add some vibrancy to your summer, decorate your patio with impressive pot/container displays or grow a ready supply of cut flowers – Dahlias can do it all.
- Why Choose Dahlias?
- Dahlia Tubers
- How to grow Dahlia plants in pots or containers
- More Dahlia Tutorials
- How to plant and grow dahlia tubers
- Fundamentals of Growing Dahlias
Dahlias are native to Mexico, and the country’s national flower. The Aztecs grew Dahlia tubers as a food crop, and they were widely used there for their nutritional and medicinal properties long before being propagated for their beauty.
It wasn’t until 1789 when the plants were sent to Abbe Antonio José Cavanilles, Director of the Royal Gardens of Madrid, that they got the name we know them by today. Named after the famous 18th Century botanist Anders Dahl, Dahlias were then developed and cultivated to the wide selection of hybrids and varieties we have today – with 42 different species.
Why Choose Dahlias?
- They are easy to grow, and suitable for gardeners of all skill levels. They are fast growing by their nature and will flower in the first year and for many years to come (just keep them stored and frost free over the winter).
- They are versatile and will tolerate most types of well drained, fertile soil or compost. They can be grown successfully in pots, tubs, window boxes and in borders.
- They are one of our favourite summer bulbs because of the many different types/sizes/colours available, which all look slightly different in shape, but are all equal in beauty.
- Year after year sees many new exciting new varieties introduced which means once hooked on Dahlias, you will continually be able to find and try something new.
- They flower continuously through the summer, right up until the first frost of the autumn.
- They look fantastic as cut flowers and are great for lovers of something a little different.
The main types of Dahlias available can be classified into a number of different categories, representing the main characteristics of the flower blooms themselves.
Anemone Flowering – Also known as Powder Puff Dahlias, these beauties produce unique flowers with double feathered central petals resembling a Powder Puff.
Cactus – A favourite for many years, Cactus Dahlias produce fully double pointed petals which turn backwards to create a tubular petal effect. Sometimes referred to as Spiky Dahlias, they are perfect for the border.
Dark Leaf – These Dahlias are a little different in that their foliage is not the usual green colours of most varieties. They create an abundance of flowers through the summer as expected, however the blooms appear on darker (usually purple/black) foliage.
Decorative – The largest range of large, fully double flowers with rounded petals through the summer right up until the first frosts. They produce masses of flowers for cutting purposes.
Dwarf Gallery – A range of smaller, more petite Dahlias which are perfect for the front of the border. They are prolific flowering varieties, look also great planted mixed together in pots on the patio.
Dinner Plate – As the name suggests these are the largest flowers within the range, often up to as much as 25cm in diameter (see illustration below). Try these as cut flowers and be certain to draw attention.
Pompom – Love the unusual, then these are certainly for you. Almost spherical flowers (like balls) appear through the summer. The petals have rounded tips and are curved upwards at the edges. The flower heads are also slightly flattened towards the centre.
All our Dahlias are supplied as top quality dormant tubers which can be planted straight into the place where they are bloom (their final location). Success rate from these dahlia tubers is extremely high and they are a relatively inexpensive way to create a large number of flowers from one tuber.
Dahlia tubers can be planted 10cm deep in fertile well drained soil, outdoors in spring when the frost has disappeared. They prefer to be in a sunny location and spaced at approximately 45cm apart. In areas where there is extreme cold, dig up dahlias and store in a cool peat over the winter. Apply a high potash fertiliser every few weeks in the summer to help growth and they can be dead headed when necessary.
How to grow Dahlia plants in pots or containers
A fantastic way to brighten up your patio is to introduce some Dahlias in pots/containers. The colour range is fantastic, with many unusual bi-colour varieties which will brighten up any space. Simply beautiful to sit back and look at during a warm summer afternoon.
- Once your tubers arrive safely in the post, they can be soaked overnight in a bucket of water to soak up as much moisture as possible.
- When all signs of frost have passed they are ready to pot up, giving plenty of time to get well established before the summer.
- It is recommended to place some pebbles at the bottom of the pots before adding the compost to help with drainage, by ensuring the compost doesn’t block the drainage holes.
- Fill in some compost and then add the tuber with the growing tip facing upwards.
- Continue to fill in the rest of the compost to firmly hold the tuber, making sure the growing tip at the top is peeping out and is not completely covered. This is now ready to be moved to the patio or garden area, with access to as much sun as possible.
- Water well after potting and then keep compost moist but not waterlogged as tubers will rot. You can add a liquid feed weekly during the growing season and provide some protection from slugs as they really love Dahlias.
- If growing tall varieties, insert a cane to help with growth and to keep secure.
- Little pruning is needed on Dahlias, however you can deadhead as flowers begin to fade.
More Dahlia Tutorials
Dwarf Gallery Dahlias
Q: I bought a number of dahlia tubers recently. When and how should I plant them?
A: Dahlia tubers are best planted after the soil has warmed a bit, between mid-April and mid-May. In a sunny location with soil that drains well, dig a deep, wide hole and work in a good amount of compost. Dahlias are big feeders, so mix in a half-handful of bone meal and a cup of organic flower food along with the compost.
Plant the tuber lying horizontally with the growing point, or eye, facing upward. The tubers of large-growing dahlias should go about 6 inches deep, while smaller-growing ones are better planted 4 inches deep.
If the dahlia you’re planting will grow to more than 2 feet tall, pound a stake in the hole and lay the tuber with the eye end about 2 inches from the stake. That way, you won’t skewer the tuber when you decide to stake it. Bait for slugs as soon as growth appears, but wait to water until the new growth reaches 6 inches high. After that, water regularly to keep the soil evenly moist at all times.
Mulch an inch thick with compost to keep the roots cool and reduce evaporation.
Every six weeks, work a mixture of 2 cups of alfalfa meal and about a cup or organic flower food around the drip line of the plant. Then, as long as you deadhead spent blossoms often, your dahlia should pump out spectacular blooms all summer long.
Q: Last year, the bottoms of my tomatoes turned black. How can I prevent this?
A: This is a common and frustrating problem known as “blossom end rot.” Symptoms begin with a water-soaked spot that quickly expands and often turns the entire bottom half of the tomato black and leathery. This isn’t a disease. It’s a physiological problem caused by a lack of calcium. Most of our soils in Western Washington are naturally deficient in calcium, so it’s always a good idea to incorporate agricultural lime into the soil of your vegetable garden in the fall to give it time to break down into a form usable by the plants by spring.
If you didn’t incorporate lime in fall, mixing a handful of calcium-rich bone meal into the soil under each tomato at planting time can help. Even with adequate amounts of calcium available, however, the plant won’t be able to absorb it if the soil is allowed to become too dry between waterings, or if a salt buildup occurs from using too much synthetic fertilizer.
Keep the soil evenly moist and fertilize only once by mixing in a cup of organic vegetable food at planting time. If it happens this year, don’t toss the whole tomato. Cut off the black part and eat the rest, because the taste won’t be affected.
Q: Is it true that corn gluten is a natural product that will keep chickweed and other low-growing weeds from taking over my vegetable and ornamental flower beds?
A: While looking for ways to make use of corn gluten, a byproduct of the corn-milling process, scientists at Iowa State University discovered that spreading it on the soil killed weed seeds as they germinated by drying them out in a critical stage of the process. At the same time, they also discovered that corn gluten is beneficial to existing plants by acting as a potent fertilizer.
Not surprisingly, corn gluten was patented and is now available as a popular environmentally friendly alternative to using chemical pre-emergent weed controls.
Unfortunately, in our Puget Sound climate, corn gluten has not turned out to be the silver bullet many of us hoped it would be. Researchers at Oregon State University found that corn gluten failed to prevent weed-seed germination in our area of the Pacific Northwest.
Evidently our moist spring weather allows the seeds to overcome the drying effect. The seedlings not only survive, but they thrive and get big and strong, thanks to all of that additional fertilizer. So, if you’re looking for a good natural fertilizer, corn gluten fits the bill, but at least in spring it’s not a good choice for weed control in our area.
Ciscoe Morris: [email protected]; “Gardening with Ciscoe” airs at 10 a.m. Saturdays on KING5.
How to plant and grow dahlia tubers
Dahlias are among the lowest maintenance, highest production cut flowers and garden plants you can grow. In a good year, they’ll flower from late June to early December (particularly in a sheltered spot). Dahlias come in all shapes and sizes, and are available in most of the best flower colours. They are some my favourite ever garden plants.
Soil and Site
|Dahlias thrive in most sunny situations and do best in a fertile soil, with moisture and good drainage.||Dig a hole for each one, at least 30cm square, 30cm deep, spacing for each dahlia tuber 75cm apart (depending on expected final size of variety).|
What to do with your bulbs when they arrive
Dahlias are tender tubers. Their root structures look like a bunch of salamis gathered together on a stem. All dahlia tubers will be different sizes. If you plant them out before the frosts are over, they may get frosted and die, so pot them up in March or early April, in a generous pot (at least 2 litre – I use 3 litre pots) filled with multi-purpose potting compost.
Place them in a light, frost-free place and keep the compost moist. They will have formed bushy plants by the time the frosts have ended and will be in flower by the beginning of July. Watch Sarah pot up her dahlia tubers in our quick video.
In the garden
If you don’t have anywhere to grow the potted tubers, you can put them straight into the ground when the frosts are over.
- Dig a hole 30cm deep by 30cm sqaure, cover the base of the hole with compost or manure and give it a good dousing with a full watering can, then plant the dahlia.
- On heavy clay, add grit to the planting hole. You will need a stout stake, not just a bamboo cane, to support each plant and it is a good idea to knock this in first and then place the plant by its side.
- After about a week in the ground, scatter a couple of trowelfuls of GroChar around the clump and give them another good soaking.
- Once a fortnight, feed them with a liquid balanced feed like Powerfeed Organic Fertiliser. In a drought, it’s a good idea to water them once a week, with a good flood not a gentle sprinkle.
- With the stake in place at planting, tie them in every couple of weeks. Dahlias grow very quickly once they get going and can easily break off right at the base in wind or rain if they are not securely staked.
- Choose a container which is at least 30cm (12″) in diameter and depth for optimum growth.
- Use multi-purpose compost and add a slow-release fertiliser for strong growth.
- Plant tubers as deep as you would when planting in the ground.
Keep in mind that all dahlias – even very healthy and long-standing old ones – grow at hugely different rates. Not all dahlias grow quick and fast and often more interesting varieties are slower, more delicate growers. Watch our quick video on growing dahlias in pots.
- Whether you have raised your dahlias outside in the garden or under cover, you need to pinch out the tips of the main shoot as they grow. Either with a sharp knife, or squeezed between your thumb and forefinger, remove the main shoot down to the top pair of leaves.
- You also need to remove all but five shoots sprouting from the tuber. There may be several more shoots, some of them weedy, but all but five must go. It feels brutal, but pinching out encourages bushy plants and with only five stems allowed to develop, you will get strong, vigorous growth that will produce lots of flowers.
- You could choose to grow some of your tubers to take cuttings, and turn one tuber into ten more tubers. Watch and read more about how to take dahlia cuttings…
In recent years, our winters in the South of England have been so mild that dahlias left in the ground, mulched deeply to protect them from the frost, have re-emerged fine, bulking up and flowering well before the other plants grown on in pots. You could opt for this low-maintenance regime, but you risk losing your plants if we are hit by a hard winter. Find out more about overwintering your dahlia tubers in our handy article.
Earwigs can be a problem with dahlias, eating the flowers and the leaves. The organic way of control is to position pots filled with straw upside down raised on canes dotted throughout your dahlias. The earwigs crawl into the straw in the heat of the day. At the end of the day you can bag them, burn them or release them somewhere else far from your dahlias. Slugs also love dahlias, especially when they first shoot, so protect them from the word go.
Only pick dahlias in full flower. Recut the hollow stem ends under water to avoid airlocks.
If you don’t pick every flower for the house, it’s a good idea to have an occasional blitz of deadheading. This will make them look much better and will prolong flowering. Cut heads off, removing the whole dead flowering stem.
You may also like:
- Understanding dahlia groups
- The history of the dahlia
- When to plant dahlias
During one August vacation my husband and youngest son happened upon the Swan Island Dahlia farm in Canby, Oregon (dahlias.com). “WOW!!” I was hooked.
I have now been growing dahlias for many years. There have been more successes some years that others, and I share my experiences below. Dahlias can be temperamental, so be patient until you find what works for you.
Location: Dahlias like warm sun, not hot shade and they don’t tolerate frost. They are best located in a situation that gets morning sun, but is protected some from the hot afternoon rays. Since they bloom late in the summer, the sooner you can get them started the better. They will wait for the soil to warm up before starting growth which can be hastened by planting in raised beds that warm quickly.
Preparation: Dahlias like acid soil so I add 1 cup of sulfur per 100 square feet when preparing the ground. My dahlias performed best on the southwest side of the house in raised beds with good drainage.
Planting: The tender tubers need to be planted well down in a 10-12 inch deep hole. Incorporate 2 tablespoons of bone meal into the bottom of the hole. Place the tuber on its side and drive in a sturdy stake next to it. By placing the stake now it serves as a marker, and also avoids the risk of damaging the roots or growing shoots which can happen once the hole is filled. I used 5ft 1inch redwood stake for my larger varieties. Cover the tuber initially with 4” of soil. Watch for sprouting and gradually fill in the hole as the plant grows.
Timing: Because you plant your tuber underground, and you build soil around the new growth as it comes up, you can start your dahlias early. Spring planting is always a gamble in the high Desert. We have recorded frosts as late as June 8th. Getting a head start in the spring gives you more rewards from your plants. Be prepared to protect your dahlias from a sudden frost – Walls of water, frost cloths, etc.
I started my tubers on April 5, 2014 and had my fist flower on June 1st. Choose an early blooming variety if possible. I have had late varieties that never bloomed before the first frost in the fall! If your plant does get hit with a frost, it won’t kill it, but it will have to start over.
You can also start your tubers indoors. When I tried this last year, I had more success with the tubers started outdoors. Although I can see where this might be a good option during a big winter and cold spring (If we ever get one of those again.)
Water: Dahlias love water but usually the tubers don’t need water until they sprout. In our climate (high desert) a light watering is often necessary until the plants emerge. When established you will want to give your plants a through deep watering about three times a week. I recommend a system that can deliver water to each individual plant so you don’t waste the precious resource. Hand watering is not recommended because you won’t get the necessary deep soaking needed. I have mine on a drip system which runs three times a week with a 1GPH emitter for 20 minutes. I supplemented that with a hose bubbler and flooded the beds every other week.
Fertilizer: Use a fertilizer with a lot of Phosphorus for the blooms (this is the middle number of an NPK fertilizer.) A good choice is the same one you would use for your tomato plants. Follow the package directions. Fertilize after the first 3 weeks and then once a month until September. Stop fertilizing in September to promote a healthier tuber for winterizing.
Pests: Slugs and snails love dahlias, especially little tender baby ones. Once you’ve filled in your planting hole, apply snail control around the top of your hole before the plant emerges to discourage them. Continue to apply throughout the season if the snails persist.
Later in the season as things warm up, watch for mites. If the lower leaves of your plant dry out and look like they need water, but you’ve been watering, you may have mites. Rinse the lower part of your plant to discourage mites. If you catch it early you may be able to wash them off, and remove the affected leaves. Mites won’t kill the plant right away and you’ll still get flowers on top. Normal fall frost is the first of October, so take all that into account before you resort to chemicals. Pesticides kill. Nature needs all of its checks and balances. For integrated pest management see http://www.ipm.ucdavis.edu/PMG/GARDEN/FLOWERS/dahlia.html .
Pruning: This is the hardest part. As the stem emerges from the ground, the main stalk develops two branches on either side. After three of these branching pairs form on the stalk you have to pinch out the center. This encourages lower branching of the plant and will give you a stronger plant and more blooms on top!
Staking: Staking is a must. Dahlias have hollow stems which often have to support very large (totally awesome) flowers that fall over easily, especially in our windy conditions.
Using the stake you placed at planting, every once in a while check and wrap a piece of garden twine around the entire plant with the stake in the middle, it will hold the plant up (unless you guessed wrong and your plant got too big, just add a second taller stake on the other side.) You don’t need to tie up each individual stalk.
Harvest: Sometimes this is a hard part – you might think that if you cut the flowers the plants will finish sooner, but the more you cut the more you get. One Fall I had several blooms on a couple of plants and thought we might get a frost so I cut them all off thinking that they were going to die anyway. Turns out we had a late frost that year and I was loaded with blooms after that! So now I feel guilty if I let a bloom expire on a plant without anyone enjoying it.
Cut your flowers in the cool of the morning, or evening before they are at the end of the bloom cycle. Not all dahlias are suitable for cutting, but I choose varieties that have long stems so I don’t have to cut off the immature blooms in the same bunch. Have a pail of water handy to put them in as you harvest.
In the late summer, if your plants have a lot of buds, but don’t seem to be blooming, they need more water.
Set the Bloom: Some growers feel setting the bloom extends the life of the cut flowers. One way to set the blooms is to get several small containers of plastic, or metal (not glass, it holds heat.) Put 2-4 inches of hot (160-180 degrees F) in the bottom of the container. I use an electric hot water pot. I’ve also used the microwave, but don’t use the container you use in the microwave to put your blooms in; it will be too hot since it is usually glass. Put the blooms in the cool containers with the couple inches of hot water with plenty of room for the steam to escape without affecting your flowers. Let the water cool for an hour or so, then transfer them to your vase.
Floral preservative will further extend the life of your cut flowers, although I just give my arrangements fresh water every day. The internet has many homemade preservative recipes, or you can buy commercial preservative.
A simple homemade preservative:
- 1gallon water
- 2 Tablespoons Sugar
- 2 Tablespoons Vinegar
- 1/2 Teaspoon Bleach
This is a good recipe to have, although I just give my arrangements fresh water every day. I’d like to do an experiment testing preservative vs daily fresh water or a combination to see what works best. But keeping it simple works best for me.
A subsequent article will cover lifting and storing the tubers at the end of the season.
Jane and Jenny looked at some particular flower types. They looked at some dahlias called ‘decorative’. Some of these have small flowers, but some can be as big as 50 cm across. One decorative dahlia they looked at was Dahlia ‘Golden Leader’ which had lots of flowers. Another decorative one with lots of flowers was Dahlia ‘Alpine Charm’.
Jenny had beautiful dahlias because she cares for them by using animal manure because it encourages worms, and as she says “With worms you’ve got good, healthy soil.”
Jenny recommends staking and tying all dahlias to protect them because they fall over if a strong wind comes up. The tall varieties can grow as high as 1.8 metres, so they definitely need staking.
Dahlias start to flower from around Christmas to early January, so you can plant them in October or November. It’s about eight weeks from planting to flowering. Jenny says that dahlias last about a week inside as a cut flower and make a lovely display.
Among the flower types Jane and Jenny looked at were the ‘cactus’, the ‘anenome’ which looks a bit like a Japanese windflower Anemone hupehensis , and the ‘Pompon’ which are shorter. Jenny says the pompon variety copes a lot better with rain than the taller ones because when they get full of rain or water they don’t drop. Tall ones just topple over if it’s windy or wet unless they’re staked and tied.
Jenny says that the most important tip to remember when people are planting the tubers is that you don’t water them until they yo up about 15 centimetres high, unless the soil is really dry, because they can rot before they begin to grow.
Dahlias flower through to the end of April, first week of May, then Jenny suggests that you start to cut them back to about half their height, just to tidy up the garden. By the time you do that, it’s then time when their leaves change colour to cut them off at ground level.
If your soil is well drained you can leave the dahlias in and dig them up early October and put them back. But if your soil gets wet in the wintertime, they’ll rot, so they’ll need to be lifted. If tubers are lifted, they need to be covered with dirt or sawdust because if tubers are left uncovered they can dry out completely.
Gardeners need to consider the flower type, but also the plant size and weather resistance when choosing which varieties to plant. Dahlias provide a great display in the garden and they repay fully any care you give them, with their wonderful varied blooms of the most amazing colours.
Fundamentals of Growing Dahlias
Everybody loves dahlias!
Photo, Carol Sahley
Dahlias are easy plants to grow and yield beautiful blooms from mid-summer through fall. In many respects, “dahlia culture” is similar to “tomato culture.” If you can grow tomatoes in your garden, you can successfully grow dahlias. The following notes will help you to add spectacular blooms and brilliant color to your garden!
Choosing your plants
There is a huge range of colors and forms of dahlias. (fig 1, 2) You will find many examples on this website. You can make your choice from the pictures you see here or from the pictures on the bags or from a dahlia friend’s recommendations. Just pick a couple and get started! You will enjoy spectacular color, variety and abundance of blooms from mid-July through the end of the growing season.
Getting your plants
There are several ways to get your first plants. Most major garden centers now sell dahlia tubers; that can be a very convenient way to get started (fig 3).
Virtually every dahlia society has tuber and plant sales; they also welcome guests to those events. There are a number of advantages to this approach if there is a club near to you (see list on this site). Perhaps of greatest benefit of that source of tubers or plants is the availability of expert advice on your choices! That expert advice can continue through the season; a regular feature of many of our local society meeting is a Q&A session! The tubers at a society auction will also likely be locally grown and of good quality.
Of course, there are also small businesses that specialize in selling dahlias and dahlia materials by mail order or internet (see supplier list on this site). These suppliers are real experts on dahlias and their products are reliable and of good quality.
When to plant
Your tubers can go directly into the ground in the spring when the ground has warmed and there is little chance of frost. One good guideline is to plant in the same time frame as you would a tomato. If you want blooms as early as possible, you can start the tubers indoors (fig 4) in good light about a month before planting time. You will then have a small plant ready at planting time. Dahlias can be planted as late as mid-June in most parts of the country.
Where to plant
Dahlias require a site with good drainage and partial to full sun. Pots are also increasingly popular way to grow dahlias. See other articles on this site for more information on growing dahlias in pots.
How to plant
Most dahlias need to be staked and you may want to plant a sturdy stake before you plant the dahlia. If you put the stake into the ground after the plant is growing, take care to avoid damaging the tuber or the root system. Tomato cages can also be a simple approach to staking.
Put the tuber in a hole several inches deep with the “eye” (fig 5) on the tuber facing up. The eye is the point on the shoulder, or crown, of the tuber from which the plant grows.
If you are planting a number of dahlias in the same location, they should be separated by about 2 feet to give each plant room to grow.
Protecting your plants from pests
Small dahlia plants are susceptible to slug damage. It is a good idea to manually remove slugs early each morning or to protect them with a commercial slug killer.
Japanese beetles seem to enjoy eating dahlia blooms just when they are ready for a bouquet. One of the best methods of control is to manually remove the beetles into a bucket of soapy water.
Other insects can become a problem if you would like your blooms to be “perfect!” If that is the case, you might want to consider using an insecticidal soap or a commercial pesticide. Follow label directions carefully if you choose to do that.
Dahlias take well to an organic approach to gardening. They are strong, robust growers with lots of blooms, including very large blooms. They do well in soil with lots of organic content even in the absence of chemical fertilizers. Pest control is not essential and can be reasonably well accomplished without resorting to chemical pesticides.
Our suburban shrubbery and gardens are increasingly susceptible to damage by deer. The good news for dahlias is that they are low on the deer’s list of favorite foods. While dahlias are not “deer proof,” they are considered to be so in some parts of the country – probably those areas where deer find enough other plants they prefer to eat!
Watering and fertilizing
Young dahlia plants do not need a lot of water; in fact, excessive water can lead to rotting of the plant. For larger plants, a good rule of thumb is to water if the rainfall is less than one inch in seven days. Pots require more regular watering.
The best strategy for fertilizing is to begin with a soil test to determine pH and the specific soil needs. Lacking that information, the plants will generally benefit from regular treatments with a water soluble or granular fertilizer. Traditional wisdom for dahlias is to treat with a high nitrogen fertilizer through the middle of the season but minimize nitrogen at the end of the season.
Maintaining your plants
There is a substantial regimen that can be used for maintaining plants for show blooms. For the simple enjoyment of spectacular dahlias in your garden, there are two relatively simple actions that will enhance the appearance of the plant. First is tying the plant to the stake several times as it grows. The first tie should secure the lower portion of the plant’s stalk to the stake. Subsequent ties should secure the branches. A simple alternative to tying is to use a tomato cage to support the plant. Then, no tying may be required.
Second is disbudding. Remove the outer two buds from the three that develop at the end of each branch (fig 8). While that reduces the total number of flowers, many flowers remain and those show up well on the plant. If all three buds are left on the stem, the blooms will tend to be covered up and can be lost in the plant (fig 6). You can also remove some of the shoots that form along the branch to have stems that can be used in tall vases for elegant bouquets.
End of the season
Your dahlias will continue to bloom prolifically right up until frost (fig 7). A heavy frost will kill the plant and leave you with a decision on your next step. You can do nothing with the plant. You will then need to plan on a visit to the local auction in the spring for the following year’s plants. Or, you can dig and discover that the plant has produced a half a dozen or more tubers like the one with which you started. If you wish, those tubers can be stored and grown by you and a couple friends next spring! Go to Dahlia University for information on harvesting and storing your tubers.