Growing zucchini in pots

Eight Ball Zucchini

Summer Squash

Cucurbita pepo

Culture: Tender, will not survive frost. Sow in hills 4′ apart, 5 seeds/hill. Thin to 2–3 best plants. Floating row covers, especially when used in low tunnels, provide extra heat and can hasten maturity by 1 to 2 weeks. Male blossoms typically precede females by about a week. Females have a bulge at the base of the blossom, an early stage of the fruit forming. In early summer, a combination of cool, cloudy weather and declining bee populations may result in poor pollination causing low yields. Mites and colony collapse disorder have wiped out a high percentage of wild and domesticated honeybee colonies in the last 20 years, creating a real crisis for cucurbit growers. Don’t leave oversized squash on the vines. It shuts down production. Make succession plantings to ensure harvest through the entire frost-free season, insurance against powdery mildew and other diseases tiring old plants. Minimum germination temperature 60°, optimal temperature range 70–90°. Days to maturity are from direct seeding.

Taste: Unless you want to stuff them, for best flavor pick squash when they are small. Squash blossoms are a delicacy. Harvest male blossoms when fully open for salads or stuffing.
Pests & Diseases: To combat squash bugs without using pyrethrum or neem: Protect young plants with row covers. Striped cucumber beetles and squash bugs overwinter in squash residues so burn or haul these away at season’s end rather than cold composting them. By hand-picking them in June and July, I reduced an endemic problem and almost completely eliminated squash bug damage.

  • PM: Powdery Mildew
  • WMV: Watermelon Mosaic Virus
  • ZYMV: Zucchini Yellows Mosaic Virus

Pest: Striped Cucumber Beetle
Cultural controls: use tolerant or resistant varieties, rotate crops, till under crop debris soon after harvest, use floating row covers until flowers appear, use plastic mulch, perimeter trap cropping (Black Zucchini and Blue Hubbard make particularly good trap crops), use yellow sticky strips, hand-pick early morning when beetles are very sluggish.
Materials: Surround, Pyrethrum (PyGanic).

Pest: Squash Bug
Cultural controls: rotation, till in cucurbit debris before winter and plant a cover crop, boards on soil surface near squash will attract bugs overnight which can be killed, avoid mulching. Squash bugs lay their brown-brick red egg clusters on the underside of the foliage, often next to the central vein—destroy egg clusters on undersides of leaves.
Materials: Pyrethrum on young nymphs, AzaMax.

Pest: Squash Vine Borer
Cultural controls: butternut squash is resistant, maximas & pepos susceptible; rotation, plow in squash vine debris soon after harvest, use floating row covers, watch for wilting plant parts and destroy borer within.

Disease: Powdery Mildew
Controls: Use small plots to slow spread, plant indeterminate (viney) varieties, control weed competition.
Materials: sulfur and whole milk, mineral or other oils in combination with potassium bicarbonate, Actinovate.

Disease: Bacterial Wilt
Cultural control: Striped Cucumber Beetle is vector—control it; choose resistant varieties.

Zucchini

Zucchini is an ideal plant for the beginner vegetable gardener because it is quick and easy to grow. Zucchini or courgette (Cucurbita pepo) is closely related to cucumber, watermelon, pumpkin and squash. There are also many ways to use the prolific fruit.

Planting schedule

Warm: April – September except for arid areas where September is the best.
Temperate: September – January
Cool: October – January

In temperate and cool areas it is best to sow seeds in small pots (try making them out of newspaper) indoors or in a greenhouse since they do not like cold weather. They usually germinate in 1 – 2 weeks and can be planted when there are several true leaves. In warm areas, direct sow seeds.

Position

Find a sunny spot with at least 6 hours of sun per day. It is best that they are sheltered from wind since their large leaves can catch the wind and cause damage to their soft stems. In exposed locations a trellis or some other form of support will be needed.

Because zucchini plants are large and sprawling, leave about 50 – 60 cm between them. You might sow seeds or plant seedlings closer and then thin them out to the desired spacing.

Talking Dirty

Like most fruit and vegetables, zucchini like good well-draining soil – raised beds will provide appropriate drainage or plant on a slight mound of soil.

Feed Me

Add plenty of compost or aged manure a week or so before planting and then again when flowering starts.

What about the water?

Since the fruit are very fleshy, zucchini need plenty of water – irrigation 2 – 3 times per week or a thorough deep hand watering once per week. It is important to avoid watering the leaves, especially late in the season when mildew and other diseases can be a problem. Don’t worry if the leaves wilt on very hot days – they will recover as long as the roots zone is watered regularly. Mulching with pea or lucerne straw will help keep soil moist.

Are we there yet?

Zucchini have separate male and female flowers and, like most species, it is the females that product fruit. The male flower grows directly on the stem of the plant in the leaf axils (where leaf meets stem) on a long stalk, and they are slightly smaller than the female. The male flower grows directly on the stem of the plant in the leaf axils (where leaf meets stem) on a long stalk, and they are slightly smaller than the female. Inside the flower, females have a rounded stigma whereas the male has a long stamen with pollen on the outside.

This is important to recognize if you find that flowers are forming but they bloom and fade, with no fruit growing afterwards. It could be that your garden lacks pollinators especially in recent years when bee numbers have been declining. If this occurs, you could try hand pollination. Use a fine paint brush in the mornings and carefully brush it against the male stamen and transfer pollen to the female stigma.

Planting other flowering plants, especially nasturtiums, which are a good companion plant for zucchini, will help attract bees to your garden.

Fruit usually appear 5 – 8 weeks after planting. Zucchini need to be regularly harvested to encourage continuous cropping. They are usually harvested quite small and immature as allowing them to continue growing results in fruit that is too big to be used as a vegetable. So watch carefully since once they start appearing since they can grow rapidly producing large unwieldy fruit. It is best to harvest when they are around 12 – 20 cm long.

The flowers are also edible – this is a good way to use the occasional excesses of male flower. They can be used in salads, as garnish, and even fried or stuffed with cheese, bacon, mushroom or tomato and baked.

Pests and the rest

Few pests cause serious problems for zucchini but, like all Cucurbits, they can be susceptible to a range of fungal diseases. In particular, powdery mildew, but this is easily eradicated. Another potential problem is blossom end rot, which isn’t a contagious disease, but is caused by calcium deficiency.

Varieties

Zucchini are available in a range of shapes and colours, not just the familiar dark green sausage-shape that is readily available in supermarkets, but yellow, striped in different shades of green and even curved or almost round. For example, ‘Blackjack’ is a prolific bush variety with very dark-green long fruit, and ‘Golden’, is a yellow-skinned variety. A number of seed suppliers stock a variety of heirloom varieties that are worth investigating, including ‘Crookneck Early Summer’, which is very suited to those who aren’t able to harvest fruit as frequently, as they remain an edible size for much longer than other varieties. There are also more compact varieties, such as Cocozelle, which means you don’t need to provide support or have a large garden space.

Information sources:

Yates Garden Guide, 42nd Edition, 2006, published by Harper Collins Publishers.
Blazey, C., The Australian Vegetable Garden – what’s new is old, 2001, published by New Holland Publishers.
Wikipedia

How to Grow Zucchini

Days to germination: 4 to 8 days
Days to harvest: 60 days
Light requirements: Full sun
Water requirements: Frequent regular watering
Soil: Well fertilized with good drainage
Container: suitable for some bush varieties

Introduction

Like tomatoes, zucchini is another popular favorite with home gardeners. Healthy zucchini vines can produce a huge harvest each year, and many people end up trying to give away their extra zucchini because they have so much of it. It’s often called “summer squash” as well.

Most zucchini varieties grow as a spreading vine, which can take up a lot of space. You can conserve space by training the vines up a trellis, and there are also some bush varieties. Most zucchini are long and tube-shaped but there are some round varieties too.

Zucchini is a very flexible vegetable that can be used either raw or cooked. You can even use zucchini in baked goods, like bread or muffins. They are very high in vitamins A and C, manganese and fiber.
Starting from Seed

Zucchini plants can be started from seed either indoors, or directly in the garden. You should start your zucchini seedlings indoors about 2 weeks before your last frost date. Zucchini grow very long roots, so start your seeds in small pots that are several inches deep and be very careful not to break the roots when you transplant. The seeds should be planted about 1 inch below the surface of your potting soil.

Because you can get 16 or more fruits per vine, you really don’t need that many plants. Three or four is usually enough for a family. If you get too over-zealous, you will almost certainly be overrun with zucchini at harvest time.

Alternatively, you can sow the seeds directly outdoors after the threat of frost is past and the soil has warmed up. See the transplanting section for more on planting right into the garden.

Transplanting

You should plant your zucchini in the sunniest part of the garden, and they love the heat.

If you are planting your seeds directly into the garden, plant the seeds about 1 inch deep, with about 6 seeds to a small hill. If they all sprout, thin down to about 3 plants per hill.

With seedlings, you have to prepare your garden area by digging the soil thoroughly so that it’s loose. To protect the roots, you should loosen the soil at least 6 inches deep. If you are using larger seedlings, you may want to dig deeper. Mix in compost or aged manure, for these heavy-feeding plants.

As mentioned, zucchinis have long tap roots, so you need to be careful when you transplant that you don’t break the roots. Dig a hole deep enough that you can set in the seedling without having to fold up the longer roots.

If you are planting more than one hill of zucchini, you should allow plenty of space between them. Bush plants need at least 3 feet on all sides because they will get quite large. Vining zucchini that are being grown upward on a trellis can be about a foot and a half apart.

Growing Instructions

Water your zucchini frequently and don’t let them completely dry out, especially once they start to set fruit. Give them a good soaking about once a week. Take care while watering to keep the water off the leaves as much as you can to reduce any problems with fungus or mildew.

Once the plants have grown to a decent size, their broad leaves will help keep the area weed-free by shading out invading plants. To keep your vines thriving, give them a good doze of fertilizer each month of the summer.

You can control the amount of fruit you get from each vine by picking the extra blossoms off once a few zucchini have begun to form. If left to themselves, a zucchini vine will keep on producing all through the summer until the weather gets too cold. The blossoms don’t have to go to waste either. Add them to a summer salad for some color. They’re edible and tasty.

Containers

Zucchini generally isn’t considered a container-friendly vegetable, but there are a few varieties that grow in a fairly compact bush that would work in a large container. Little Gem or Eight-Ball form bushes with fruit in the middle instead of long vines, and work fine. Your container should be 2 to 3 feet across, and at least 3 feet deep.

Pests and Diseases

There are several pests you need to watch for when growing zucchini. When it comes to insects, Striped Cucumber Beetles and Squash Vine Borers are your worst enemies. The beetles are fairly obvious on the leaves and blossoms and can be picked off by hand. Organic insecticides with pyrethrin can work quite well. If you are really struggling with beetles, you may want to even cover your young plants with a light sheet of mesh netting until the blossoms form. You need to remove it though, or your plants won’t get pollinated.

The vine borers are hard to deal with because they dig into the stalk, making them very hard to detect until your plant is already dying. You can cut into the stalk (along the length, not across) and pick out the insects, which may or may not kill the plant anyway. If you bury the cut portion, it may heal and even grow new roots.

For diseases, you need to watch for wilt and powdery mildew. Bacterial wilt can be spread by cucumber beetles, which is another reason to control those insect pests. If your plants develop wilt, there is little you can do. The leaves will turn yellow, and wilt right to the ground. It can happen practically overnight. Pull up the plants before others get infected.

The other threat is powdery mildew, which looks like powdery dust on the leaves of the plants. It thrives in humidity, so do your best not to wet the leaves during watering. Also, water the plants early in the morning so any water on the leaves can dry before nightfall. You can spray the plants with a fungicide as soon as you see the powdery spots. The effected leaves will eventually yellow and drop off.

Harvest and Storage

And while it might be tempting to let your zucchini grow really large, the best flavor comes with the smaller fruit. Large ones start to get woody, and the seeds are getting hard inside as well. Pick them around 6 to 10 inches long. They will grow quite quickly, so plan on checking the vines every couple of days.

It’s almost inevitable that one or two zucchinis will be missed, and you will discover a huge one growing in a corner somewhere. You can still use it, but it will likely work best grated in a baked recipe (like muffins).

Handle the fruit carefully once you’ve picked them off the vine. The skin is very thin and it can get scratched or bruised easily. Zucchinis don’t hold their flavor very long after picking. You can store them in the fridge but should use them up within a week.

  1. Craig Says:
    March 16th, 2012 at 5:12 pm

    How often should you water and for how long. I like to grow squash(summer and butternut)zucchinis, beats, carrots, tomattos,beans, and pumpkins but can never tell if I’m over watering or underwatering. My dad use to do the watering for me when I was younger and I believe he watered every day for probably 5 to 10 minutes but I’m not positive as we got older we got built in sprinklers and they got watered every morning for 15 minutes but if I’m using a hose that seems to be way too much water to me. Any advise?

  2. Dave Says:
    July 5th, 2012 at 7:08 pm

    Thanks for the useful info about growing. One slight mod is suggested: zucchini squash is a poor source of Vitamin A, and only a modest source of Vit. C and fiber. The manganese content isn’t included in USDA nutrient data, so I don’t know how you have decided it is a good source of this trace mineral. I would doubt it, though, because the various squash species are generally not good sources of most trace minerals. However, like most plant foods, squash is a good source of potassium.

    Nutrient values can be easily looked up here: http://ndb.nal.usda.gov/ndb/foods/show/3247

  3. bill Says:
    July 8th, 2012 at 2:52 pm

    my zucchini plant roots on not deep and no luck in containers

  4. Shelly Says:
    July 9th, 2012 at 7:18 am

    I found a bag of old opened potting soil in my shed. It was dry and didn’t look fresh. Does potting soil go bad or could out door animals cause any kind of fungi or bacteria that will kill plants if I used it?

  5. Lin pierce Says:
    July 29th, 2012 at 10:41 am

    We’re growing a second crop of zukes and yellow squash as we lost many to squash borers. I know it is recommended to pile dirt over the stems after squash borer “surgery” has been done as the plants can then grow some new roots. This made me wonder if planting new seedlings deeper than what is usually recommended would help to make the new plants stronger, say up to the first set of leaves like we do with tomato plants? Is this worth trying?

    Also, No fear of squash borers now as their cylce has the caterpillars coming out in late June, right?

    Thanks for your attention.
    Lin

  6. Shaun McMahon Says:
    April 3rd, 2013 at 10:21 am

    To grow in containers how important is the size of the container? – can you grow Raven zucchini in a 1′ by 1′ container

  7. Claudia Says:
    May 1st, 2013 at 7:42 am

    should i cover my zucchini in the hot afternoon sun

  8. bill Says:
    May 25th, 2013 at 11:23 am

    if not interested in eating zucchini blossoms,should I leave them on the plant or pluck them off?I have heard that removing the blossoms promotes growth though I’m skeptical.Thanks

  9. Meredith Says:
    May 30th, 2013 at 11:53 am

    Our Zuccini plants have grown and blossoms have come and gone and still no zuccini. I’m worried because the plants have grown so big it looks as if the roots are exposed. Should I add more soil or is this normal?

  10. Barbara Thomas Says:
    June 18th, 2013 at 4:33 pm

    Our zucchini plants have blossoms but no zucchini growing from them> Do we need bees to pollinate?
    Our plants look very healthy.

  11. Nick Says:
    June 27th, 2013 at 12:04 pm

    Hi, im wondering if growing them up a trellis is a good idea or would they rather grow them on the ground? Im a first timer for growing zucchini as i am only 15 and i love gardening, just trying for some good tips from someone who is experienced and knows whats going to happen. P.S. im in zone 5 and only have one plant

  12. john mcleish Says:
    June 29th, 2013 at 1:05 pm

    Hi,
    my 2 plants are growing brilliantly in containers and I am training them up supports in my greenhouse.
    The problem is that the plants produce huge flowers that eventually fall off but there is no fruit on the bare stem.
    As a novice to growing this plant can you give me advice on watering, feeding and pollination.
    Thanks John

  13. susan Says:
    July 5th, 2013 at 8:35 am

    my zucchini plant got sooo big the leaves are really big and covering the zucchini and the zucchini doesn’t get to big and then they get rotten and die off what should i do. should i cut some of the leaves down

  14. Debbie Woods Says:
    July 6th, 2013 at 1:42 pm

    I have two huge plants that I got at a greenhouse!! I would like to know if you can or should trim back the leaves a little and are the stems eatable? Thanks for all the good tips I read above!!

  15. Jack Dwyer Says:
    July 11th, 2013 at 8:22 am

    my zucchini plant got sooo big the leaves are really big and covering the zucchini and the zucchini doesn’t get to big and then they get rotten and die off what should i do. should i cut some of the leaves down

  16. Scott B Says:
    July 15th, 2013 at 3:35 pm

    I have two zucchini plants and am seeing some success but some of the fruit starts to shrivel and turn yellow. Is this an over watering issue or something else?

  17. Scott B Says:
    July 15th, 2013 at 3:37 pm

    Plants are doing well but some of the fruit is wilting and turning yellow at about 3-4 inches. Is this a water issue or something else?

  18. karen morgen Says:
    July 16th, 2013 at 6:19 am

    Our zucchini plants are very large and have flowers but I see no signs of veges. any suggestions? Do the flowers come first?

  19. Pat Says:
    July 20th, 2013 at 5:49 am

    I too grew zucchini in the ground this year and the leaves are so large that they are covering my pepper plant and tomato plants. Can I cut some of the leaves off to give my plants some sun. I am not worried about having a bumper of zucchini.
    Thank you,

  20. Tracy Johnson Says:
    July 21st, 2013 at 9:49 am

    Hi. I am growing summer squash. I have seen alot of blooms but they leaves below it turn yellow and die. I need help what should I do?

  21. Susan K Says:
    July 21st, 2013 at 3:49 pm

    Someone gave me 7 zucchini seeds, and I got 6 started and planted in back of my condo. They’ve taken off without much care, and I’m learning as I go, but I just harvested my first zuke — about 6 inches. Yay. Questions: should you cut off the dead leaves? (There’s a rule against planing veggies in my condo community, so want to keep them “pretty” and under the radar.) Also, are they annual or perennial? Do you leave them to bloom again or remove them in fall?

  22. Jen Says:
    July 29th, 2013 at 6:13 pm

    So this may be a dumb question, but I’m totally new to the garden scene. When you say hills need to be so far apart and you can have X # of plants per hill, how big are said hills? I feel dumb asking this but I’m planning on making a good sized garden in my back yard next year and doing away with trying container plants as I don’t have much luck. I want to get all the info I can now so I can do this right come next spring. Also with different plants requiring different types of soil do I just put said soil in the hole of said plant and not over the entire garden? How do I get different types of soil? When I go to my local homedepot I only see a bunch of bags saying veggie soil. If there is like a gardening for idiots website or something please let me know 😉

  23. KRE Says:
    July 29th, 2013 at 9:36 pm

    I am a balcony gardener. My question is can I trim the excess leaves and male blossoms that are in abundance? Of the eight seeds planted four of them have only male blossoms. I’ve had to “paintbrush-pollinate” the few female blossoms due to lack of bees & bugs on the third floor flat I live in. Thank you for your help

  24. Julie Says:
    July 30th, 2013 at 9:10 am

    This year ,I have put zucchini plants in my back yard.
    They produce large leaves and flowers but 4 in. zucchinis and they
    are rooting from the stem. I have cut some of the very wide leaves still no results. What do I need to do?

    Thank you

  25. Administrator Says:
    July 31st, 2013 at 8:18 am

    @KRE – do not trim excess leaves, there is no such thing as an excess leaf. Those leaves all produce energy which feeds fruit production.

    Yes you can trim excess male blossoms… and the best thing to do with them is to eat them. You can stuff them, batter them, and deep fry them, or pan fry them, or add them to stir fry or pasta dishes. They don’t keep long so it is best to pick them the day you intend to eat them.

  26. Susan Oldfield Says:
    August 4th, 2013 at 10:32 am

    my zucchini in a pot starts good zucchini, and then they seem to turn yellow and shrivel.

  27. Administrator Says:
    August 11th, 2013 at 2:33 pm

    IF your female flowers are not developing fully into zucchini, you need to hand pollinate as the bees are slacking.

    See here: http://www.gardeningblog.net/2012/08/01/how-to-hand-pollinate-squash-zucchini-pumpkins-cucumbers-and-watermelons/

  28. Rick Says:
    August 13th, 2013 at 1:14 pm

    I’ve grown beautiful zucchini plants in the ground with plenty of flowers, but I’m not getting any fruit. What am I doing wrong?

  29. Konrad/Judy Says:
    March 28th, 2014 at 6:25 pm

    what is the difference from Mexican type?

  30. Deborah Says:
    April 17th, 2014 at 5:57 am

    Thank you for the great information. I live in Wetumpka, Alabama and had a very successful first year zucchini crop last year. This year, I want to harvest some of the zucchini blossoms. How is that accomplished and does it affect the zucchini produce?

  31. Dean Says:
    July 4th, 2014 at 3:31 pm

    Hi there Iam wondering why my zucchinis grow to about 6inchs and then they die….please help we love them BUT cannot grow any……HELP
    THKS DEAN

  32. Gloria Says:
    June 19th, 2015 at 5:25 pm

    I see your comment about NOT cutting excess leaves. I have been doing this for years and still got many zucchini’s. If I don’t cut some extra leaves the leaves will cover other plants and they don’t grow. Does cutting stems/leaves really hurt the plant? What about cutting off the flowers before they even bloom.

  33. lori Says:
    June 29th, 2015 at 9:26 am

    I find this a bit strange but I harvest a garden every year of yellow squash, zucchini, tomatos, cuccumbers…etc.. well this year I decided not to go so big and just do tomatos and cucumbers. well to my surprise I have a squash or a zucchini plant growing, since I did not plant and leaves look very similar , I’m not sure which one it is. is this possible for this to grow without me even planting that this year only in prior years. ??????

  34. Administrator Says:
    December 24th, 2015 at 6:46 am

    Left over seeds in the soil… we call these “volunteers.” You have a volunteer squash plant.

  35. Sohan Says:
    July 23rd, 2015 at 5:23 pm

    Our zucchini plants are growing and flowering but the fruit does get around three inches long ant rots. What we are doing wrong?

  36. Administrator Says:
    December 24th, 2015 at 6:37 am

    Try manual pollination. This is what happens when the flowers do not get pollinated.

  37. chris Says:
    April 21st, 2016 at 3:38 pm

    i put black beauty heirloom zucchini in my raised bed thats 10.5 inches tall. will that be enough root room for them? please tell me they’ll be fine with about 8-10 inches of soil,very,compost, and peat moss mix???

  38. Administrator Says:
    April 23rd, 2016 at 4:32 am

    yes

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Zucchini Container Care: Tips For Zucchini Grown In Containers

If you love zucchini but you’re short on gardening space, consider zucchini grown in containers. It’s true that zucchini plants can take up a lot of space, but growing zucchini in container gardens on your patio or balcony isn’t as difficult as you might think. Read on to learn about container grown zucchini.

How to Plant Zucchini in Pots

A container with a diameter of at least 24 inches and a minimum depth of 12 inches is best for container grown zucchini. Any type of container works well as long as it has at least one good drainage hole in the bottom. For example, a large, plastic storage container with drainage holes drilled into the bottom makes a good planter. If you want to grow more than one plant, consider a half whiskey barrel.

Zucchini grown in containers requires a lightweight, well-drained potting soil such as a commercial mix containing ingredients like peat, compost and/or fine bark, along with either perlite or vermiculite. Avoid regular garden soil, which probably contains pests and weed seeds, and quickly becomes compacted enough to smother the roots.

You can easily plant zucchini seeds directly in the pot about two weeks after the last frost in your area. Consider compact, dwarf plants such as Cue Ball, Gold Rush, Eight Ball, especially if you’re growing zucchini in a smaller container.

Plant two or three seeds in the center, at a planting depth of about an inch. Allow a couple of inches of space between each seed. Water the soil lightly and keep it slightly moist but not soggy until the seeds germinate in a week or two.

If all of the seeds sprout, thin them after about two weeks. Remove the weakest and leave a single, strong seedling.

Zucchini Container Care

Once the seeds sprout, water the zucchini plants deeply whenever the top 2 inches of soil feels dry to the touch, then allow the top of the soil to dry before watering again. Zucchini is a sun-loving plant that needs an absolutely minimum of six to eight hours of sunlight per day; eight to 10 hours is even better.

Feed the zucchini plants every four weeks, using a balanced, water-soluble fertilizer. Alternatively, mix a time-release fertilizer into the potting mix at planting time.

Depending on the variety, zucchini plants will likely require stakes to support the long vines. A tomato cage inserted into the container works very well. Install the cage at planting time to prevent accidental damage to the plant. Dwarf varieties may not require staking.

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