Cauliflower can be a thought-provoking veg to grow in the home garden . It has very specific needs , and when they are n’t meet , your harvest basket may be full of fleeceable leaves , but no head .

And while the foliage is delicious , it ’s a disappointing time of year finale .

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A close up, top down picture of green cauliflower foliage, the white veins and stems clearly visible against the light green of the leaves.

In this article , we ’ll consider 11 reasons for cauliflower not organise head .

Why Isn’t My Cauliflower Forming Heads?

1. Wrong Seed

Sometimes a harvest is doomed from the kickoff . This is likely to be the case when you purchase seed that is not suited to yourUSDA Hardiness Zone . Cauliflower thrives best with logical temperature ranging from 60 to 70 ° farad .

Be sure toread seed bundle carefullyand opt varieties with days to maturity that match your clime ’s growing season . Decide if you ’ll found a spring or fall craw , or both . Explore the latest cultivars that have improved temperature tolerance and shortened ripening periods .

2. Seedling Stress

Cauliflower is temperamental throughout its development , especially during the germination and seedling phase .

For ripe results , start seed indoorsabout four to six calendar week before the last predicted frost date in natural spring . This is preferred to lead sowing , because it gives seedlings a chance to become established before facing out-of-door conditions .

graft seedlings about two weeks prior to the last average Robert Frost date in your region , when they have develop at least two sets of lawful foliage . The background should be at least 50 ° fluorine .

A close up of a cauliflower plant with large dark green leaves on the outside, with smaller leaves in the center but no sign of a head forming. To the center and bottom of the frame is green and white text.

Do n’t wait too long to transplantation , or your seedling may become pot - truss , with solution that enwrap around and around fail to return water and essential nutrients to the developing plant

If your climate allow for a capitulation crop , wait until the medium air temperature has drop to at least 75 ° F , by and large about eight weeks before the first frost .

seedling necessitate a period of gradual acclimatization to the out-of-doors call “ season off . ” Without it , stale shock may retard increment and have a detrimental effect on development .

A close up of a cauliflower plant with large dark green leaves on the outside, with smaller leaves in the center but no sign of a head forming. To the center and bottom of the frame is green and white text.

Poorly tended seedlings may appear to thrive , but if they have suffered stress they might not constitute heads as expect .

3. Lack of Sun

Members of theBrassicagenus like cauliflower , broccoli , cabbage , andkohlrabirequire full sun to thrive . Without at least six hour of sunshine per 24-hour interval , results may be disappointing .

If your region has afternoons that are really too red-hot for cauliflower growing , you may try imbed in fond shade . However , growth slack without sunlight , and you might find your plants are still set on leaf when they should be forming heads .

4. Soil Deficiencies

Organically - rich soil is best for Brassica oleracea botrytis . It ’s a clayey feeder , sodo a stain testand set the nutrient cognitive content of your garden . ameliorate the dirt as require with theaddition of compost , well - aged manure , or humous .

Soil contains macronutrients like nitrogen , phosphoric , and potassium , the N - P - K that you see on fertilizer label . It also contains other macronutrients include atomic number 20 , and micronutrients such as copper . Micronutrients are typically found in lesser amount .

Imbalances in the soil may leave in short nutritive intake , resulting in accent that may cause failure to form heads .

A close up image of light brown cauliflower seeds on a green background, fading to soft focus at the edges of the frame.

One food that ’s difficult to measure is N . While Brassica oleracea botrytis utilise a good bit of it to grow , too much of this macronutrient is known to do excess leafage product .

Therefore , if you fertilize your vegetables , you should choose a slow - release type in which the ratio of N is slenderly less than the atomic number 15 and K components .

A territory test also determine pH , and answer as a measure of sour or alkalinity . For Brassica oleracea botrytis , the pH should be neutral to more or less acidulous , or about 6.5 to 7.0 . You may increase acidity with the gain of copious organic issue , or decrease it with anapplication of garden lime tree .

A hand from the right of the frame, with a dark blue gardening glove is holding a cauliflower seedling over a freshly dug hole, ready for planting. In the background are further seedlings and soil in soft focus.

wretched soil that is devoid of nutritive constitutional matter , as well as soil with a pH that ’s too acidic or too alkaline , may contribute to direct formation bankruptcy .

5. Inadequate Drainage

While cauliflower requires consistent moisture , it should never digest in a pool . Its roots need to take what they require to aliment the plant life and have the residual drain by .

Poorly drain ground result roots vulnerable to nibbling nematodes , slug , and snailsthat can impair the ability of the plant to take up water and nutrients . In accession , these insects may spread disease to weakened plants .

If your Brassica oleracea botrytis has systematically besotted ft , it may fail to get heads .

A close up of a small cauliflower seedling planted in rich dark earth in bright sunlight. The background is soft focus soil.

6. Insufficient Moisture

This veggie is one of the thirstier ones . It needs one to two inches of water each week , soget yourself a rainfall gaugeto varan rainfall , and ready to supplement as needed .

With some vegetable , you could get aside with keeping them moist during the germination and seedling phases , and then allow Mother Nature provide the rain they need .

But this is not so with Brassica oleracea botrytis . If you let it dry out out , it ’s likely to put up emphasis that can lead to bolting , buttoning , or no head formation .

A close up, top down picture of a bright green cauliflower seedling in the ground, in bright sunlight. The bright green of the foliage contrasts with the dark earthy soil.

Keep in mind that it ’s not only a deficiency of sufficient rain and failure to irrigate with supplemental piddle as needed that may leave your crops at danger of drying out . Wind may speed up moisture evaporation as well . So , if the weather prognosis is a puffy one , protect plants with well - anchoredfloating course cover version .

7. Overcrowding

When transplanting seedling , space them out with 24 inches between plants , and 30 to 36 inch between row . This allows for ample flow of air and origin formation , essentials for healthy development .

Circulating air stay cool and less humid , helping to suppress fungous diseases that are prejudicial to cole craw development .

Roots that can distribute without competition from neighbor are better capable to hydrate and aliment a industrial plant .

To the right of the frame a hand holding a hosepipe with a spray attachment watering a newly planted cauliflower seedling into dark rich earth. To the left of the frame is a black plastic punnet with further seedlings ready to plant. The background is soil in soft focus.

8. Pests and Disease

sizable plants are less vulnerable to the ravages of infestation or infection .

In increase to meeting light , filth , piddle , drain , temperature , and spacing requirement , cauliflower cultivator demand to be vigilant about keeping weeds to a lower limit . Thick dope ontogenesis creates competition for piss , and invites insects who can hide out and be near their favorite veg at the same time .

Pleaseconsult our clause on grow cauliflowerfor detail on how tomanage common pestsanddiseases , as they can induce enough tension to result in failure to form header .

Two rows of cauliflower plants growing in the garden, in between the rows is soil, contrasting with the green leaves. The background is vegetation in soft focus, and the image is bathed in light sunshine.

9. Failure to Rotate Crops

Rotating crops is n’t just for farmers .

Growing vegetables feed on dirt throughout the growing season , run through its nutrient . Changing locations from season to season let ground to replenish . As an impart bonus , it also assist to keep cuss and disease at bay .

If you ’re not rotating your crops , your soil may become spent , and thus unable to leave decent nutrition with poor point organization as a result .

A close up of a cauliflower plant with its foliage damaged by pests. The leaves are pock marked and have holes in them. The background is vegetation in soft focus.

10. Immaturity

Sometimes what seems like a flora ’s nonstarter to forge a head is in reality due to a misapprehension of the identification number of days to maturity date .

look on the variety , cauliflower needs between 50 and 100 growing daysto be harvest home - ready .

While this information is provided on source packet , it ’s easygoing to forget . If you ’ve run across the plant ’ needs so far , be patient and hope for the good .

A top down close up image of a cauliflower plant with a very small head developing, between the small leaves in the center of the plant. The white of the head contrasts with the deep green foliage.

11. Temperature Fluctuations

You need to be a piece of a weather condition junkie to grow good Brassica oleracea botrytis , because this is one stubborn veggie . It just wo n’t budge when it come to involve temperatures that are n’t too stale or too raging .

So , once you ’ve chosen ejaculate that ’s appropriate for your region , monitor atmospheric condition prevision and be proactive .

Mulch is proceed to be your newfangled best booster . It keeps plant coolheaded when the atmospheric condition warms up , and retains estrus when temperatures duck . It also helps with wet retentiveness .

A close up of harvested cauliflower heads, tightly packed together with their leaves trimmed.

In addition to mulch , you could place lightweight specter cloth over plants to head off the Dominicus ’s re during a heatwave .

And conversely , during a cold snap , apply floating row covers with their end snugly unopen to organise a quick cocoon . These also inhibit wind - ride moisture evaporation .

Favorable Odds for a Successful Crop (With a Bonus Tip)

At any leg from seedling to blush with foliage , a Brassica oleracea botrytis plant may experience accent that could alter the course of study and consequence of its growing .

Along the way , you might have plants bolt in the heat energy and go to seed . Or , they may button or Elmer Rice , leave behind you with open little curd . And finally , they could die to set a psyche whole .

Despite these challenges , or maybe because of them , cauliflower ’s allurement for dwelling gardeners is strong . Knowing the 11 possible problems outline above – and forfend them – put you out front of the game .

When you lastly see the crowning glory of your effort nuzzle in the winding foliage , go back to that ejaculate packet and see if you have a ego - blanching kind .

If not , there ’s one more crucial whole tone to success , and that contribute us to our bonus tip :

You must gently wrap several of the longest leaves over the developing head to protect it from “ greening ” in the sunlight that has substantiate it for so long . generally join them with clothespins so you could still peer in to watch it reach the size indicated on that all - important cum packet .

Not turn a loss a head to sunburn is the final hurdle , and then you ’re home free … stop a sudden difficult freeze , or a late - season heatwave .

Once you ’ve get your cute harvest time , why notvisit our sister site , Foodalfor forward-looking cauliflower recipes ?

It ’s meter tochoose your favorite cauliflower varieties ! Start planning for the time of year ahead . This class ’s vegetable garden is certain to be your best yet .

If you found this article informative , you ’re sure to savor some our othercauliflower originate guides :

© Ask the Experts , LLC . ALL right wing RESERVED.See our TOSfor more details . in the first place published November 22nd , 2019 . Last update August 18th , 2023 . Uncredited exposure : Shutterstock .

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Nan Schiller