Success with Growing Cabbage in Spring

Young Early Jersey Wakefield cabbage, a fast maturing pointed variety.
Photo Pam Dawling

Some of this material is from my book Sustainable Market Farming.

Cabbages can be reliable workhorses, providing large harvests over long periods. In colder regions, cabbages are planted only in the spring and grow all summer, into the fall and winter, until cold weather kills them. In the South, they are a spring/early summer and a fall/overwintered crop, as it’s too hot to grow them in the summer. In parts of California and the Pacific Northwest, they’ll grow year-round.

Cabbage crop requirements

Cabbages do best on fertile, well-drained soil with adequate moisture. They require a lot of potassium, so a sprinkling of wood ash, kelp meal or granite dust could be helpful. Calcium, boron, iron, manganese and molybdenum are also important for good brassica crops — healthy, biologically active soils can usually supply enough of all these. If not, amend as needed.

Young Farao cabbage, a good fast-growing round variety.
Photo Pam Dawling

Cabbage varieties

Be clear about what kind of cabbage you are looking for, especially whether it’s for fresh eating, slaw, sauerkraut or storage, and what size you want and how many days from seeding to harvest.

  • For quick-maturing cabbage, we choose Early Jersey Wakefield (63d OP), Golden Acre (62d OP) and Farao (64d F1) (All days to maturity in this list are from transplanting in spring. Add 14 days for direct sowing. Subtract 10-14 days for warm weather sowings.)
  • For large solid cabbage for making sauerkraut, we choose Gunma (110d F1), Tribute (103d F1) or Early Flat Dutch (85d OP)
  • For a green cabbage that holds well in hot weather, to extend the season as long as possible, the flat Tendersweet (71d F1) is tasty and works well for us. It is good for coleslaw and wraps, but not for storage
  • We like a red that’s fairly large and yet quick-maturing (many reds are too slow for us, taking us deep into hot weather). We used to favor Super Red 80 (73d), but gave it up after two poor years. Ruby Perfection (85d F1) stores fairly well, as does Integro (85d F1)
  • We like savoy cabbage, and find Melissa (85d F1) and Famosa (80d F1) quick and reliable
  • For storage we have liked Storage #4 (95d F1), Kaitlyn (94d F1), and Late Flat Dutch (100d OP)
  • Deadon (105d F1) is a particularly cold-hardy one to grow into the winter. It survives down to at least 10°F (-12°C)
  • High Mowing and Johnny’s Seeds have good selections of over twenty cabbage varieties, including the 77d 10-17 lb (4.5-7.7 k) Megaton, good for fresh eating and kraut.

Sowing cabbage seed

A seed flat of cabbage and several flats of spotted out seedlings in our greenhouse in February.
Photo Pam Dawling

In early spring, transplants have the advantage over direct-seeded crops — they grow faster under protected conditions and bring earlier harvests. At other times of year, you may prefer to direct seed.

Work back from your desired harvest date to calculate the sowing date. Naturally you’ll need to allow for your climate and choose a realistic transplanting date. We start our very first cabbages in our greenhouse in mid–late January, as soon as I’m mentally prepared to start a whole new year. Maincrop cabbage follows in mid-February.

Despite being a cool-weather crop, brassicas actually germinate very well at high temperatures: the ideal is 77°F–85°F (25°C–30°C), and 95°F (35°C) is still OK. Given enough water, the seedlings will emerge in four and a half days at the low end of this range, and at the top in only three days. The minimum temperature for good germination is 40°F (4.5°C), but you’ll need to wait more than two weeks for emergence if it’s that chilly.

We start our spring cabbages in home-made open wood flats, sowing 3–4 seeds per inch (5–10 mm apart). We press a plastic ruler 0.25″ (6 mm) deep into the seed compost to make a small furrow, spacing the rows 2″–3″ (5 cm) apart.

Once they have emerged, the seedlings need good light, nutrients, airflow and protection from bugs. 60°F–70°F (15°C–21°C) is a good temperature range for growing them. As soon as the seed leaves are fully open, we spot (prick) them out to 4″ (10 cm) deep flats, with 40 plants per 12″ x 24″ (30 x 60 cm) flat. The plants grow to transplanting size in these flats.

Spotting cabbage seedlings from a seed flat into a transplant flat.
Photo Wren Vile

For the last two weeks before transplanting, harden off the plants by moving them into cooler, breezier, brighter conditions.

Transplanting cabbage

We grow spring cabbage in 4′ (1.2 m) beds, at two rows per bed, with plants 18″ (50 cm) apart. Mini-cabbages can be spaced at 8″–12″ (20–30 cm) in the row, with rows 12″–18″ (30–45 cm) apart, and may give higher total yields as well as heads of a more useful size.

We aim to transplant at four true leaves (5–8 weeks after sowing in spring). This is early to mid-March for the earliest cabbage (seven weeks old), very early April for maincrop cabbage. Soil temperatures of 65°F–75°F (18°C–24°C) are ideal. Optimal air temperatures for most brassicas are 60°F–65°F (15°C–18°C).

Water the seedlings well before transplanting, and plant all the way up to the base of the first true leaves to give the stem good support. Press the soil very firmly around the plants so the roots have good soil contact and won’t die in an air pocket. I was taught to tug on a leaf after transplanting: if well planted the leaf will tear and the plant will remain in the ground. Water within half an hour of planting and again on the third and seventh days, and then once a week.

Young spring cabbage with a hay mulch. Wren VIle

For cabbage, the sixth and seventh leaf stage is the most vulnerable. If the weather deteriorates at this critical time, give your plants extra protection. High daytime temperatures can to some extent compensate for low nighttime temperatures — it’s cold days and cold nights together that do the damage. We use thick rowcover over our spring cabbages for a few weeks after transplanting, then may switch to insect netting.

Two weeks after transplanting, we check the plants and fill the gaps with transplants we have kept for this. If it is necessary to use big plants to fill gaps, we pinch off a few of the lower leaves to reduce their water needs.

Caring for  cabbage in spring and summer

About a month after transplanting maincrop cabbage (mid-May), we remove the rowcovers and the sticks we use to hold them down.

We use only overhead sprinkler irrigation (not drip tape) for spring cabbage, which helps cool the leaves and can wash off aphids. Organic mulches help keep the soil cool, as well as adding lots of organic matter to the soil. Brassica roots are relatively shallow, so long droughty spells without irrigation can cause problems. One inch (2.5 cm) of water per week is about right.

One of our impact sprinkler tripods, in a broccoli and cabbage patch.
Photo Pam Dawling

Cabbage pest control

Using rowcovers or insect netting keeps many pests off the plants while they are small. We have not had much trouble with aphids, perhaps partly because of our overhead sprinklers; insecticidal soap sprayed three times, once every five days, can usually deal with them. Our worst pest is the harlequin bug. When necessary, we handpick them. Ladybugs are reputed to eat harlequin bug eggs.

Sometimes we have had enough cabbage worms to make Bt (Bacillus thuringiensis) necessary, but usually paper wasps eat the caterpillars. The action threshold is an average of 1 cabbage looper, 1.5 imported cabbageworms, 3.3 armyworms or 5 diamondback moth larvae per 10 plants. Below this level you can do watchful waiting rather than spraying with Bt or spinosad. Apparently paper or plastic fake cabbage moths on sticks will deter more from moving in. There are templates for homemade cabbage moth decoys online. The eyespots are important!

Yarrow flowering in our hoophouse in late November, 13 months after sowing.
Photo Pam Dawling

We are also lucky enough to have the naturally occurring wasp parasite of cabbage worms, the Braconid wasp Cotesia species, which are found as small cottony white or yellowish oval cocoons in groups on brassica leaves. The Cotesia wasps like umbelliferous flowers, and overwinter on yarrow as well as brassicas. If you find Cotesia cocoons and your brassicas aren’t diseased, you can leave plants in the field over winter. Or you could collect up leaves with cocoons in late fall and store them at 32°F–34°F (0°C–1°C) until spring. Hopefully no one will clean out your fridge without asking.

To float out worms and aphids after harvest, soak the produce in warm water with a little vinegar for up to fifteen minutes, then rinse.

Harvesting cabbage

Our cabbage heads up from May 25 and some hold till July 15. For storage cabbage (a valuable crop in summers in warm climates with scarce fresh leafy greens), we set the cut heads upside down on the stump, in the “basket” of outer leaves, and come back an hour later to gather them into net bags. This allows the cut stem to dry out and seal over, improving storability.

Mature Farao early cabbage. Note the curling-back leaf on the head, a sign of maturity.
Photo Pam Dawling

Sowing beets, radishes and kale, transplanting cabbage.

Cylindra Beets. Credit Southern Exposure Seed Exchange
Cylindra Beets.
Credit Southern Exposure Seed Exchange

In line with my advice in the August issue of Growing for Market magazine, we are working on our First Chance to start again with the spring and fall crops. We sowed beets, and I found out I meant to order more seed before this point. In spring we sowed our beets with the Earthway seeder,EarthWay rather than our more usual manual sowing of lightly soaked seed. I was working on my own and rain was approaching, so I just used the seeder with dry seed. The radish plate was best for the Cylindra beets, if I remember right. Consequently I used more seed. We’ve managed to sow of the three beds we intended.

I put in a hasty online order to Fedco. After clicking Send I remembered we need more carrot seed too. Argh! Happily the people at Fedco are so helpful that they agreed to my email request to add carrot seed to the order. We love buying from Fedco. They don’t waste our money on glossy catalogs. They offer great bulk discounts. And the newsprint catalog is full of pithy comments on food politics. Fedco is one of the main three seed companies we buy from – along with Johnny’s and Southern Exposure Seed Exchange

We did have enough carrot seed to complete our large fall planting (3 beds of five rows at 265′ – almost 4000ft). But we want to try a slightly later bed of carrots to overwinter. It worked well last year – the voles stayed away. Last August I blogged about fall carrot planting in my post Risking zombie carrots. The year before we ended up not managing to weed all our fall carrots, so we mowed them for weed control, then left them overwinter. We were able to harvest them in the early spring.

Vates dwarf Scotch curled kale Photo by Kathryn Simmons
Vates dwarf Scotch curled kale
Photo by Kathryn Simmons

Today we sowed winter radish and two beds of Vates kale. Next up are turnips and more kale. We sow two beds every four days until we have enough established. The rain today is perfect. I think the first two beds should have no problem germinating. The rain will also help the big carrot planting. I have been running a sprinkler overnight on them, but it takes five nights to get all the way to the bottom of the patch. And one night the well meter stopped working and it stopped the water running. So that night was a loss as far as irrigation went. We did the pre-emergence flame-weeding of the carrot beds on Saturday, thinking they might germinate Monday (and no-one wanted that flaming job on Sunday), but in fact they only started germinating this morning.

Flame Weeding. Credit Brittany Lewis
Flame Weeding.
Credit Brittany Lewis

Our evening transplanting shifts have gone very well. If it isn’t raining too hard this evening, we should be able to finish tonight. That’s a mere ten shifts. Sometimes it takes us a lot longer. The unknown is how much time we’ll need to spend replacing casualties, but I think 3 evenings max. We have run the drip irrigation every evening while we are working there, and some more on dry days. We’ve had some rain too, which helps. I haven’t had a thorough look under the rowcovers, but there are shadowy green things in most of the right places, so I’m optimistic. The peculiarly mild temperatures have made transplanting the overgrown plants easier than it could have been. Feels like we are making up for lost time.

Summer reading

GFM-August 2013-cover-300px

 

The August issue of Growing for Market magazine is out (the June-July issue was the most recent previous one). This one includes my article on Last Chance Sowings.

In line with my advice, at home we are busy preparing beds and sowing beans, bulb fennel, cucumbers and squash. As well as being our last chance with these warm weather crops, it’s now our first chance to start again with the spring and fall crops such as carrots, beets, kale, scallions, turnips (no rutabagas for us these days – it needs extra time to grow to a good size, and we’re never ready soon enough). It’s too soon for us to sow spinach (although the weather is surprisingly cool for August!) – we wait till the fall chickweed, dead nettle and henbit germinate before sowing spinach. we’re also out in the garden every evening transplanting broccoli and cabbage. We’re over half way, and the mild weather is really helping.

Cutting Zephyr yellow summer squash. Credit Brittany Lewis
Cutting Zephyr yellow summer squash.
Credit Brittany Lewis

Also in this Growing for Market issue are valuable articles by other growers, such as Ben Hartman on arranging their farm’s CSA into two separate seasons, spring and fall, with a two week gap in the middle. What a great idea. I got a two week gap myself, thanks to our stalwart crew keeping the crops happy while I was gone.

There’s encouragement from Lynn Byczynski, the editor,  to comment to the FDA on the proposed food safety rules for produce. cover4Jonathan Magee (author of the book Small Farm Equipment) writes about irrigation pumps, which will likely be a big stress-saver for anyone who has stood in exasperation over a non-working pump. Andrew Mefford writes about useful tools for the hoophouse, including some nifty little Harvest Scissors, worn like a ring, freeing up the hands to alternate with other tasks while working.Erin Benzakein, the regular writer on cut flowers, covers ideas for early spring blooms, and, as always, has some beautiful photos.

For the next issue I am writing on strawberry production systems, including our latest method – using landscape fabric with holes burned in it.

2013-berry-veggie1-80x300My presentation on Planning Fall Crops at the Virginia State University Commercial Berry and Vegetable Field Day  on June 27 is now a full blown video. you can view it at their website, along with those of the other presenters; Reza Rafie on specialty crops such as baby ginger, Steven Pao on food safety and Debra Deis from Seedway Seeds on their variety trials.

I’ve recently found a website I think will be very useful for help in predicting pest outbreaks, as well as counting accumulated Growing Degree Days and recording the weather. It’s called My Pest Page. It’s for the technically minded. To modify our page for your area, start with the map and zoom out then in again on your area, using your nearest weather station. Then you can choose which pieces of information to have displayed, by clicking on the plus button by each topic to expand the list of options. Then click on the big Refresh button and bookmark the site. I see we’re now at the point when Late Blight infection is possible. . . , so I’ll keep my eyes open.A few years ago when we thought we had Late Blight on our tomatoes we spent a lot of time removing infected leaves into trash bags. When we sent a sample to the plant diagnostic clinic they said we didn’t have Late Blight. I think it was a heat stress condition caused by us using the wrong kind of drip tape. (We had too much on at once, so not all the plants were actually getting the irrigation we thought they were.)

Talking of irrigation, It’s time I left my desk and went to switch over to today’s fourth sub-system.