Workhorse Crops for May

Workhorses crops are reliable under a wide range of conditions, including weather, soil, date and other variables. Some are easy to grow, some pump out lots of food, some are “insurance crops” like chard that stand in your garden until you need to harvest them, some are especially profitable (for those growing for market).

I’ve chosen 14 crops (including two pairs) to focus on in the next 12 months, ending April 2022: Asparagus, beans, cabbage, carrots, chard, garlic, kale and collards, potatoes, sweet corn, sweet potatoes, tomatoes, watermelons, winter squash, zucchini and summer squash.

My motivation for this series is to help all who want to be more efficient, productive and profitable (if selling) as other parts of our lives expand again.

Workhorse Crops to Plant in May

May is a busy planting month here in central Virginia and probably most places in the northern hemisphere. Ten of our 14 Workhorse Crops can be planted once frosts are behind us.

Beans: We grow bush beans because we don’t like putting up trellises. In the past we had uncontrolled Mexican Bean Beetles that destroyed slower-to-mature pole beans. We found we could get crops of bush beans faster and sow them every few weeks or so to get a good supply of presentable beans every couple of days. Click this link to read about soaking bean seed, using inoculant, sowing through biodegradable plastic mulch using a jig, sowing sunflowers in our bean rows as place-markers when harvesting. See my phenology post for information on when it’s warm enough to start sowing beans (and other crops) where you are.

Carrots: I wrote a lot about carrots in the past year, when the monthly series was on root crops. See this post on preparing beds for sowing carrots, and weeding and thinning. Check out this post on flame-weeding, if you plan lots of carrot-growing!

Chard: A great insurance crop – it provides leafy greens when you need them, and you can ignore it when you have plenty of other vegetables! As a biennial, chard will not bolt the first year (unless stressed by lack of water). We use chard for fresh greens in summer, when kale, collards, broccoli and cabbage from the spring have long gone. Because we don’t need chard until late May, we don’t sow until late March. We transplant in late April, into a hay mulch. This crop will be in the ground until mid-winter, and mulch will keep back most of the weeds. You could, of course, sow chard earlier if you want to eat it earlier. We also grow chard through the winter in our hoophouse, where it feeds us during the Hungry Gap.

Potatoes: I wrote a special series on potatoes last year. Click the link to access the whole series, starting with planting in April. Here we plant in March and June. You can plant at any date in between, so long as you have 80 days until your first frost. If time is a bit short, choose a fast-maturing variety (or be satisfied with small potatoes that won’t store).

Sweet corn: we make 6 sowings of sweet corn, to harvest from July 4 to mid-October. Start planting sweet corn when the leaves of the white oak are as big as squirrel’s ears. Click the link to check our planting dates, and to read about our first sowing of the year, catching raccoons and skunks, avoiding mixing types of corn and to view my slide show on succession planting. There’s a confusing aspect of hybrid corn varieties: if you plant a mixture of different genotypes, it can lead to starchy unpleasant-flavored corn. Also don’t plant Indian corn, popcorn or any kind of flint or dent corn within 600′ (180 m) of your sweet corn. For this reason we grow only sweet corn in our garden.

Sweet potatoes: I wrote about planting sweet potatoes in 2020. Modern varieties of sweet potatoes grow to a good size in as little as 90 days, so they are not just for the South! The further north you are, the longer the daylight at midsummer and the more photosynthesizing the plants can do. I have known people grow sweet potatoes in hoophouses if their climate isn’t warm enough outdoors. This can fit with winter use of the hoophouse for greens and roots. My book Sustainable Market Farming contains a whole chapter on this crop, including growing your own slips, but it’s too late to start that this year. Wait for the soil to warm before planting out your sweet potato slips. We plant ours a couple of weeks after the last frost, around the time we transplant peppers and okra.

Tomatoes: We plant out our main crop at the very beginning of May, unless the weather is too cold. To my surprise, I find I haven’t written much about transplanting tomatoes outdoors. Here’s a post about planting tomatoes in our hoophouse. We use the same techniques in the hoophouse and outdoors. We transplant one row of tomatoes down the centerline of a 4ft (1.2 m) bed, 2ft (60 cm) apart. Outdoors, once the weather has settled so that we’re confident we won’t need rowcover any more, we stake and stringweave. We install a steel T-post every two plants (4ft /1.2 m) apart and start stringweaving when the plants are about 12ins (30 cm) tall. I’ll say more about stringweaving later in the year.

Watermelons: Watermelon growing isn’t easy, but the rewards are so wonderful, that I gave watermelon a “Circus Pony” place among the workhorses! We transplant our watermelons, to get ripe ones as early as possible. Melons are tricky to transplant, as the roots don’t do well if disturbed. We have successfully used soil blocks, and these days we use Winstrip 50-cell trays. Watermelons grow very well on black plastic mulch, which warms the soil as well as keeping weeds at bay. The first year we switched from using hay mulch to biodegradable plastic mulch, we were astounded to get ripe melons a full month earlier!

It’s important to keep the little seedlings in the greenhouse warm and in very good light, and away from drafts. Be careful not to overwater. They can keel over very quickly and once the stem collapses, remove that seedling before others die too. The goal is short stems!

When you transplant, get the start out of the flat and into the ground as quickly as possible with as little root damage as you can manage. This is not a crop where one person plops the plants out down the bed and someone follows planting them! Make the hole in the soil (through the plastic if you’re using that), by wiggling the trowel from side to side. Don’t dig a hole as if you are in a sand box, with a spoil heap at the side. Just form a space the right depth to get the whole of the stem in the ground.

Next gently pop the transplant out of the flat, perhaps using a table knife down the side of the cell. Push up from underneath. If all goes well, you’ll have the plant in a little block of soil (yes, like a soil block). Slide the transplant into the hole. You want all the leaves above ground, all the roots and stem in the ground. If the hole is too deep, lift the transplant carefully and scrape some soil into the hole. You don’t want to end up with the plant in a dip, as this can rot the stem. If the hole is not deep enough, you can to some extent hill up soil around the stem to protect it. You don’t want any of that fragile stem visible!

Water the day before, and one hour before transplanting, to help the soil hold together, and so that the plant has some reserves of water to see it through the initial shock of being set out. As you are transplanting, pause and water newly set plants every 20 minutes or so. Afterwards, water the whole planting and repeat on the 2^nd, 3^rd, 5^th, 7^th days and once a week after that.

Winter squash: By contrast, winter squash are very easy, and they store for months at room temperature. A true workhorse. We direct sow at the end of May, with the goal of harvesting in September and October, the last ones making Halloween lanterns. Soil should be at least 60°F (15.5°C), and all danger of frost should be past.

We have grown about 400ft (120 m) for 100 people, and mostly focus on Butternuts, Moschata types that grow best where we are and store longest. This is the type to focus on if you want trouble-free squash, with no damage from borers or cucumber beetles. The tougher stems are better able to repel invaders. They need warm growing temperatures above 60°F (16°C). As well as Waltham Butternuts, we include the large Cheese pumpkin, the long-storing Seminole, and the gigantic Tahitian Butternut. We also grow a couple of Maxima squashes which store quite well:  Cha-cha kabocha, and the large blue Jarrahdale, which have relatively high resistance to squash bugs compared to others in this group. Red Kuri, Festival (sweet dumpling type) and the New England Pie pumpkin are Pepo squashes, suitable for storing a few weeks only. (Pumpkins are squashes.) We grow some of these because they are sooner to harvest. Really they are more of a fall squash than a winter squash.

Winter squash do need a lot of space for each plant. This can mean a lot of hoeing until the vines spread, or mulch. Some can take 90-120 days to reach maturity, so plan carefully to be sure of getting a harvest. For dryland farming, without irrigation, it is important not to move the vines to new positions: the dew and rain drips from the leaf edges encourage root growth directly below the vines (where they get the most water and shade).

Sow 0.5”-1” (1-2 cm) deep. Either “station sow” 2 or 3 seeds at the desired final spacing, or make a drill and sow seeds 6” (15 cm) apart. There are various stick planters and jab planters that can be used for this kind of station sowing. Thin later. Rows will need to be 6’ (1.8 m) apart, or more. 9’ (2.7 m) between rows for the vining ones. Some growers plant in a square pattern so that spaces between rows can be mechanically cultivated in both directions. Bush varieties take less space than the vining types, and rows can be 4’ (1.2 m) apart.

You can transplant winter squash if you need to. We did this one year after our fields flooded. We started seeds in cell packs a week before our usual sowing date of 5/25. It worked just fine.

Zucchini (courgettes) and summer squash: Zucchini is a subset of summer squash. These are easy to grow, fast to produce warm weather crops. We make a succession of five or six plantings each year, so that we can harvest every day. Each sowing is half a yellow squash (Zephyr, Gentry) and half a zucchini (TenderGrey, Noche, Golden Glory). We grow our earliest squash in the hoophouse, setting out transplants at the beginning of April. Our first outdoor crop is also from transplants. After that, the soil is warm enough to direct sow – 60°F (15.5°C).

After transplanting or sowing, we hoop and cover the row with insect netting (rowcover also works if it has no big holes). We have many bugs that like these plants, especially the striped cucumber beetles, so we keep the rows covered until female flowers appear. At that point we need the service of the pollinators, unless the squash is parthenocarpic (sets fruit without pollination). At that point we pack away the covers, hoe and thin the squash to 24” (60 cm). it would be better to thin sooner, but we rarely find the time.

Zucchini and summer squash are another crop type that we succession sow, to get a continuous supply. More about succession planting another time. The time from sowing to harvest is only around 50 days.

Workhorse Crops to Harvest in May

Asparagus can be harvested if you have a patch. If not start to prepare a patch to plant out one-year crowns next early spring. Remove all perennial weeds while growing a series of cover crops. If you have asparagus, you probably know to snap off at ground level all the spears above a certain length. We chose 7” (18 cm). Do this every day for the 8-week harvest period. Daily harvest will also remove asparagus beetle eggs, controlling the pest level.

Cabbage can be ready from late May, if you made an early sowing of fast-maturing varieties. Farao or Early Jersey Wakefield can take only 60 days.

Carrots can be ready from late May, if you sowed some in mid-late February

Chard is ready for harvest from late May (earlier if sown earlier), see above.

Garlic scapes appear in hardneck garlic plants. Here it is also an indicator that our garlic will be ready to harvest in three weeks.

Kale and collards can be harvested until they are bolting, as long as the flavor is acceptable. Read more about bolting here.

Zucchini and summer squash from mid-May,

From storage: carrots, potatoes, sweet potatoes, winter squash

Workhorse Crops Special Topic: Deciding Which Vegetable Crops to Grow

Here’s a slideshow to help you decide which crops to grow. Some of the points are for commercial growers, some apply to anyone growing vegetable crops.