How to Grow Kale from Store Bought
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How to grow kale from store bought starts with knowing which form you bought. For this guide, store bought means one of two forms: seed or a transplant. The Utah State University guide names both as ways to grow kale, and the University of Arkansas and Montana State University give timing, spacing and harvest guidance that agrees on the main points. This guide follows those steps from planting through storage, and it marks where the sources stop.
Quick answer
- Choose the form first. Seed takes longer, while a transplant gives an earlier crop, according to the Utah State guide.
- Plant from early spring to early summer, or in late summer for a fall harvest, as the Arkansas guide describes.
- Space plants 8 to 12 inches apart in the row. The sources give slightly different figures, so the table below shows the counts for each.
- Water deeply and steadily, and pick the lower leaves while they are small and tender.
Seed or transplant: which one you have
The Utah State guide puts the choice in one sentence: “Kale can be grown from seed or transplants.” It explains the trade-off too. Transplants are “used to provide earlier harvest,” which is the main reason to buy a started plant rather than sow seed in the bed. The same guide sets a standard for a transplant, and it is the standard to check at the garden center: transplants “should have 4-6 mature leaves and a well-developed root system before planting.”
If you start your own transplants at home, the Utah State guide says it takes time to reach that size: “Generally 5-6 weeks are required to grow transplants to this size.” Work backward from your planting date and allow those weeks. For broader ideas on which crops suit a raised bed, see our guide to vegetables for raised beds, and for a beginner list, see our easiest vegetables to grow in raised beds.
Site, soil and varieties
The Arkansas guide lists kale’s basic conditions: a sunny spot, well-drained soil, medium-rich fertility, a pH between 5.6 and 7.0, cool temperatures and moist conditions. The Utah State guide adds a step before planting: work “plenty of organic matter and a complete fertilizer into the area before planting.” It describes kale as preferring fertile, well-drained soil rich in organic matter.
Varieties differ in how long they take. The Utah State guide names three and says they “have excellent production, eating quality and cold hardiness”: Starbor, which it lists at 55 days, Red Russian at 50 days, and Scarlet at 55 days. Arkansas also lists cultivars with days to maturity, but the table in the copy we retrieved is hard to read, so this guide relies on the Utah State names.
When to plant
The Arkansas guide gives the widest window: “Plant kale any time from early spring to early summer.” For a fall crop, it adds: “Planting in late summer provides harvest from fall until the ground freezes hard in winter.” It also says “Late summer planting usually gives best results,” which makes late summer the safer target for a harvest that lasts into the cool season.
Transplants follow a different calendar, tied to the last frost. The Utah State guide says to plant them “4-5 weeks before the last frost free date for the growing area.” Montana State gives a soil temperature rule for both seed and transplants: direct seed or transplant kale “when soil temperatures have reached a minimum of” 40 degrees F. Check your own last frost date with your local Extension office before you set a date.
Temperature limits the summer window. The Utah State guide says kale does best when temperatures stay below 75 degrees F, and that young plants are not seriously damaged by temperatures down to 25 degrees F. Heat is the limit to plan around for summer sowing.
Planning a fall crop
The Utah State guide gives the arithmetic for fall kale: “For fall kale, select early maturing cultivars and plant 50-75 days before the anticipated maturity date.” It sets the target for the harvest as well: “The maturity date should be about 2-3 weeks after the first fall frost.” Count back 50 to 75 days from that target, and choose an early-maturing variety for the late-season bed.
The Utah State guide also says plants “can be left in the garden throughout the winter to supply greens out of season.” A fall crop therefore has two harvest windows: the first picking after frost, and any later picking the weather allows. The sources do not say how long the winter picking lasts in a given region.
Sowing seed step by step
The Arkansas guide gives the depth for seed: “Sow seed 1/4 to 1/2 inch deep in rows.” The Utah State guide gives the same range with its own wording: “Seeds should be planted ¼-½ inch deep and thinned when plants have 3-4 true leaves.” Sow in rows, and thin once the plants show three or four true leaves.
Thinning is the next step. The Arkansas guide says to “Thin the seedlings to 8 to 12 inches apart.” The Utah State guide adds a practical point: “Plants removed at thinning can be transplanted to adjacent areas.” The thinnings can go to nearby spaces rather than being discarded, which is the guide’s own suggestion.
The table turns the three spacing figures into plant counts for one 10-foot row.
| Guide | Spacing stated | Plants in one 10-foot row (our arithmetic) |
|---|---|---|
| University of Arkansas | 8 to 12 inches (after thinning) | 120 ÷ 12 = 10 to 120 ÷ 8 = 15 |
| Utah State University | 12 inches, rows 2 feet apart | 120 ÷ 12 = 10 |
| Montana State University | About 8 inches between plants, 18 to 30 inches between rows | 120 ÷ 8 = 15 |
The counts above use 120 inches for a 10-foot row. They are our own arithmetic, since none of the guides gives a plant count. Montana State’s spacing is an approximate figure, while the Utah State figure of 12 inches applies to both seeded and transplanted kale.
Water, feeding and mulch
Kale needs steady moisture. The Utah State guide says to “Water kale deeply and infrequently while trying to maintain even soil moisture,” and it puts the weekly need at “About 1-2 inches of water.” Irregular watering costs quality: “Moisture fluctuations will cause leaves to become tough and develop off flavors.” Arkansas describes the crop as easy in other ways: “Kale are relatively easy to grow, requiring only normal cultivation and watering.”
Feed with care. The Utah State guide suggests a nitrogen-based fertilizer about four weeks after transplanting or thinning. It says to place the fertilizer “6 inches to the side of the plants” and water it in. Montana State advises fertilizing mainly when plants are stunted or their leaves turn yellow.
Mulch helps with moisture. The Utah State guide lists “Organic mulches such as grass clippings, straw, and shredded newspaper” and says they “help cool the soil, reduce water stress and help control weeds.” It advises applying organic mulch once temperatures rise above 80 degrees F.
Heat, frost and season length
Heat changes both growth and taste. Arkansas says “Although kale tolerates summer heat, it grows best in the spring and fall.” Montana State puts it more bluntly, saying kale “does not thrive in high summer heat.” The Utah State guide ties heat to flavor: “High summer temperatures reduce growth, decrease quality, and cause bitter or off flavors to develop.”
Cold weather works in kale’s favor. The Utah State guide says “Frosts help improve the flavor of the fall planted crop.” Arkansas adds that “Kale can be harvested until a severe freeze in the winter.” Together, the two sources show why a late-season bed is often the better choice for a leafy crop.
Harvest and storage
Pick the lower leaves first. The Arkansas guide says “The lower leaves may be individually picked when they are small and tender (8 to 10 inches or shorter),” and the whole plant can be cut if you want it all at once. The Utah State guide agrees that older leaves come first: “Older leaves are generally stripped off the plants first allowing the young leaves to continue to grow.”
Montana State gives a leaf check. It says to “Choose small to medium leaves with a dark green appearance” and to “Avoid brown, yellow, wilted or slimy leaves.” The same guide notes that older leaves can turn tough as the plants mature and temperatures warm, which is why picking is often steady rather than occasional.
Yield is modest per row. The Utah State guide says to “Expect 3-5 pounds per 10 feet of row,” and it suggests planting “5-10 feet of kale per person for fresh use.” Our arithmetic on those two figures gives roughly 1.5 to 5 pounds per person for fresh use, depending on how much of the row each person gets.
For storage, Montana State says to “Store kale unwashed in a bag in the coolest part of the refrigerator for 3-5 days.” The Utah State guide gives a longer window under cold, humid conditions, about 2 to 3 weeks, but the Montana State figure is the one for a home refrigerator.
Mistakes to avoid
- Cutting out the center leaves. Arkansas says that “Removing the apical meristem prevents further growth.”
- Planting into midsummer heat. Arkansas says kale grows best in spring and fall, and Utah State warns of bitter flavor in high summer.
- Skipping the thinning step. Arkansas gives 8 to 12 inches as the final spacing.
- Letting the soil swing between wet and dry. Utah State links fluctuations to tough leaves.
- Waiting too long to pick. Montana State notes that older leaves get tough as the crop matures.
How we chose
We read store bought as seed or transplant, because those are the two forms the sources describe, and we wrote the guide from that reading. The guide draws on three extension pages: the University of Arkansas Division of Agriculture bulletin FSA6069, the Utah State University Extension page “How to Grow Kale in Your Garden,” and the Montana State University Extension kale fact sheet. Each was opened with curl on 2026-10-23, and every quoted sentence appears in the text we retrieved. Retail seed packets, garden center pages and company blogs were left out, since they do not give growing guidance the way extension pages do.
What we could not verify
The three sources cover kale grown from seed or from transplants. They do not say how long a store-bought packet keeps its germination rate, and they do not compare seed brands. Their timing advice depends on the region, so the windows in this guide are only as broad as the sources’ own coverage.
What the sources do not say
The sources we opened do not cover regrowing kale from a grocery-store bunch, and this guide does not claim that it works. They do not give a days-to-harvest figure that we could quote cleanly for a specific variety. They do not name a last frost date for any particular town, so each reader needs a local source for that date. The Montana State soil temperature rule is a minimum, and the pages we opened do not say how long a crop takes to start after that point.
Frequently asked questions
Can kale be grown from a grocery-store bunch?
The sources we opened do not cover it. The Arkansas guide says removing the center leaves stops further growth, so a bunch cut from the center is not a starting point the sources describe. Seed or a garden-center transplant are the two forms covered here.
Is seed or a transplant the better start?
The Utah State guide says kale “can be grown from seed or transplants,” and transplants are “used to provide earlier harvest.” Seed suits a gardener with time to spare, while a transplant suits one who wants an earlier crop and has a plant with a well-developed root system.
When is the best time to plant kale?
Arkansas says to plant “any time from early spring to early summer,” and late summer is the choice for a fall harvest. Transplants go out 4 to 5 weeks before the last frost, according to the Utah State guide.
How far apart should kale plants be?
Arkansas says to thin to 8 to 12 inches apart. Utah State says 12 inches between plants in the row, with rows 2 feet apart. Montana State says about 8 inches between plants. The table shows how many plants each spacing gives in one 10-foot row.
Why does kale taste bitter?
The Utah State guide ties bitterness to heat: “High summer temperatures reduce growth, decrease quality, and cause bitter or off flavors to develop.” It also links irregular moisture to tough leaves with off flavors, so steady watering is the other factor to control.
Sources
- https://www.uaex.uada.edu/publications/PDF/FSA-6069.pdf (opened 2026-10-23)
- https://extension.usu.edu/yardandgarden/research/kale-in-the-garden (opened 2026-10-23)
- https://fdn.montana.edu/extension/nutrition/nutrition-cooking-culture/documents/KaleFFS.pdf (opened 2026-10-23)
