Bare Root Transplants

Lettuce seed bed, with Muir, Jericho, Sierra lettuces. Photo Bridget Aleshire

Lettuce seed bed, with Muir, Jericho, Sierra lettuces.
Photo Bridget Aleshire

Last week when writing about Lettuce Varieties for January I mentioned how we grow all our outdoor lettuce as bare root transplants. From January through to the end of April, we sow lettuce seed in open flats. After that date, we sow in outdoor nursery seed beds, and simply dig up the transplants when big enough and replant them in our raised beds. We transplant 120 lettuce outdoors each week until early October and then transplant in our greenhouse and our hoophouse. We also grow many other crops (all the easy to transplant ones) in open flats, or in nursery seed beds.

This method has gone “out of fashion”, but perhaps it will come back in! Atina Diffley (Author of Turn Here Sweet Corn and Wholesale Success) has written a blog post about bare-root brassica transplants at atinadiffley.com/blog/. She has written a thorough-and-concise 9 page manual Seed Beds: Bare Root Field-grown Brassica Transplant Production.  It includes a chart of pros and cons of bare-root transplants compared to container-grown greenhouse transplants.

Using bare-root transplants does require a bit more attention to technique than popping plugs into the ground. But it’s not that difficult and we train new people every year with success.

Why bare-root transplants?

Bare-root transplants save a lot of time and money, compared to growing in flats. They also save on valuable greenhouse space. The plants get very sturdy, because they have the full depth of soil in which to develop big roots. Starts grown in outdoor seedbeds are already acclimated to cooler conditions than plants in your greenhouse. They are less prone to drying out than seedlings in flats, but do be ready to protect them from bugs.

Which crops work best?

Bare-root transplants can suffer more transplant shock than plugs, so start with “easy to transplant” crops, such as brassicas (cabbage, kale, collards, broccoli, Brussels sprouts, kohlrabi), lettuce, onions and leeks. Tomatoes and peppers are worth trying next. See the Chart “Relative Ease of Transplanting Bare-Root Vegetable Seedlings” free online in Knott’s Handbook for Vegetable Growers. Avoid trying bare-root cucurbits (squash, melons, cucumbers).

Bare-root transplants can be used on any scale, from backyard to large farm. See the impressive photos of huge beds of cabbage transplants in Atina Diffley’s manual. They can be used at various times of year, and from indoors to outdoors and vice-versa.

Spring bare-root transplants started in a hoophouse, planted outdoors.

For the earliest spring transplants, bare-root hoophouse starts are a nice option. For us, onion seedlings overwintered in the hoophouse have worked very well. Seedlings outdoors or in a cold-frame suffer too much winter-kill. We don’t want to fuss with flats in November-February. We’re in zone 7, at 38̊ N. We sow onions in the soil in the hoophouse November 10 and 20, with a backup sowing on December 5. We plant them outdoors as early in March as we can. The onions get to thin-pencil-size by March 1, which we couldn’t do from a spring sowing. Onion roots are tough and thick, not thread-like – they are easy as bare-root transplants.

We sow spinach, collards and kale in the hoophouse in mid-late January and plant them outdoors in early March. This is a lot less work than using flats, and our comparison trials with bare-root spinach showed results were just as good as spinach in Speedling plug flats. We have tried early lettuce transplanted from the hoophouse, but the plants were not as sturdy as those in flats.

Senposai, the Thousand Wonder Green, Credit Kathryn Simmons

Senposai, the Thousand Wonder Green,
Credit Kathryn Simmons

Outdoor bare-root transplants

See my book Sustainable Market Farming, for more details of growing outdoor bare root transplants. We grow lettuce this way from April to September, and fall brassicas in June and July, in one of our permanent raised beds where the soil is friable and free-draining. Also see Atina Diffley’s manual for cultivation tips.

We grow outdoor cabbage, broccoli, collard, senposai and Yukina Savoy transplants in seedbeds for 3-4 weeks in June and July, covered with ProtekNet on hoops. We transplant in July and early August for harvest in October and November. We prefer this to direct sowing, because it is much easier to keep the relatively small seedbed watered and bug-free. For large amounts use an EarthWay seeder. Atina Diffley recommends the leek seed plate for brassicas.

Outdoors to indoors

In September we make an outdoor seedbed for crops to transplant into our hoophouse in October. The late summer hoophouse crops get a few extra weeks to finish up. Because the hoophouse can be warmer than ideal for lettuce germination until well into fall, it often works better to start plants in a cooler location, then move the plants. In September in our climate, four-week old lettuce plants will be a good size.

As well as ten varieties of lettuce, we sow various Asian greens and Brite Lites chard. Nine days later we sow another ten varieties of lettuce, white and red Russian kales, senposai and frilly mustards such as Ruby Streaks, Red Rain, Golden Frills, Scarlet Frills as well as green mizuna. We cover the seedbeds with hoops and ProtekNet and water daily. Transplanting these plants starts October 1 with the fast-growing pak choy, Chinese cabbage and Tokyo Bekana. The other transplants follow, as they reach the right size.

Brassica seedbed protected from insects with ProtekNet and hoops. Photo Bridget Alsehsire

Brassica seedbed protected from insects with ProtekNet and hoops.
Photo Bridget Alsehsire

Stay indoors in winter

In October in the hoophouse we sow short rows of “brassica fillers”, mostly senposai, Tokyo Bekana and Maruba Santoh. These grow fastest, which becomes more important in the dark winter days. We fill gaps in any brassica bed, that occur either because of disease, or of harvesting. In late October and early November we sow filler leaf lettuce varieties and filler spinach. These extra plants help us out if something goes wrong, and give us the chance to grow some extra crops after the first ones have been harvested.

How much to sow

Our formula for sowing seedbeds in the hoophouse is to divide the final row length of brassica plants by 10 to give the minimum length of seed row to sow. These plants will be transplanted 10″-12″ (25-30 cm) apart. For onions (to be transplanted 4″ (10 cm) apart), we divide the number of plants wanted by 20 to give the row feet (67/m), but we sow this amount twice, about 10 days apart. Outdoors for the fall brassicas, we sow around a foot (30 cm) of seed row for every 12′-15′ (3.6-4.6 m) of crop row, aiming for 3-4 seeds per inch (0.75 cm apart). These plants will be transplanted 18″ (46 cm) apart. It’s important to weed and thin the seedlings to 1″ (2.5 cm) apart soon after they emerge.

Transplant age and size

There is quite a lot of flexibility about when a start can be transplanted, but there are accepted ideals to be aimed for. The University of Florida Vegetable Horticulture Program Vegetable Transplant Production page  has a wealth of transplant information. Transplants grown over winter or in very early spring in a hoophouse will take longer to reach plantable size than those sown in spring or summer.

Suitable conditions for transplanting

The ideal conditions for outdoor transplanting are mild windless afternoons and evenings just before light steady rain. Transplanting late in the day gives the plant the chance to recover during the cooler night hours when transpiration is slower. Shadecloth or rowcover can reduce the drying effects of wind and sun. Damp soil is important before, during and after transplanting.

Bare-root transplanting technique

When you dig up your bare-root transplants, leave some soil clinging to the roots, to help the plants re-establish quicker. They don’t need a full handful of soil for each plant. Just dig up a clump and give it a light shake, to leave the majority of the soil behind, and some still on the roots. This means less damage to the root hairs. Be sure to dig deep enough so you don’t damage the tap roots. Water your plants the day before and an hour before lifting (pulling) them. In hot weather, keep the plants as shaded as possible while transplanting.If necessary water the soil ahead of planting.

We use plastic dish-pans to carry our plants from seedbed to field, and I tell people to only dig up what they think they can transplant in half an hour, so that plants don’t sit around for too long. Push the trowel into the soil, using the dominant hand, push it forwards, shake a plant loose from the clumps in the dish-pan with the other hand, and slip a plant in behind the trowel. Pull out the trowel, keeping it in your hand while you close the soil against the stem with your planting hand and the trowel. (Efficient workers keep a hand on the trowel at all times, never setting it down.) Move to the next spot and repeat. When setting out a large number of plants, water every 20-30 minutes if you don’t have drip irrigation running (a bit less often if you do) regardless of the number of plants set out. If the person is skilled and moving fast, and the weather is not outrageously hot or windy, I might let an hour go by before pausing to water. The advantage of getting a lot of plants in the ground proficiently and quickly might outweigh the need to water more often, as the plants are not having their roots exposed to the air for as long when they are planted fast. The hand-watering really helps the soil settle around the roots, and after that the damp soil can wick moisture from the irrigation towards the plant.

Aftercare: water, rowcover, shadecloth

Water your plants the day after transplanting, on days 3, 7 and 10, and then weekly, if it doesn’t rain when you’d like it to. Shadecloth draped over recently transplanted crops can help them recover sooner from the shock in hot sunny weather. We use 50% shade, in 6′ (1.8 m) width, with wire hoops to hold the shadecloth above the plants. This improves the airflow as well as reducing the abrasion or pressure damage done to the plants. The airflow through shadecloth is better than with floating rowcovers. ProtekNet allows good airflow too, and keeps bugs off.

Shade cloth on lettuce seed bed. Photo Nina Gentle

Shade cloth on lettuce seed bed.
Photo Nina Gentle

 

 

 

Growing for Market, Organic Broadcaster, using rainy days

June2016_cover_300 pxThe summer issue of Growing for Market (June/July) has been out for a couple of weeks. We’re having a very rainy Fourth of July, so that pushed my mind towards good reading material. Assuming you stayed home and didn’t join the millions on the roads.

This issue has an interesting article by Amy Halloran about sustainably grown food grains as an addition to the crop portfolio for vegetable and flower producers. Sometimes we’re looking to diversify our crops to help the rotation (thwart the usual pests and diseases), or to even out the workload over the year. Local artisanal bakers and brewers might be looking for locally grown grain, or you can sell small bags alongside your vegetables. One advantage of grains is that they have a good shelf-life, so you can bring them out to your CSA or you market when you wan to add something new and different. Heirloom grains and dry beans have appeal for those who want to return to their roots.

Eric and Joanna Reuter wrote a helpful farmers’ guide to applying for a SARE grant. They give a clear overview explanation, then a step-by-step guide to how to apply. They talk about how to design a suitable project, how to set it up, run it, evaluate and fit with the deadlines. They include an example of a SARE farmer-directed research project that changed their farm management. It was Kevin Cooley’s pilot project using supermarket baskets (factory seconds) to harvest, wash and store vegetables. The vegetables stay in the basket they’re picked into. It saves a lot of time and reduced handling.

Wendy Carpenter wrote a very useful article reviewing use of moveable high tunnels. Five years have passed since this idea really took off, and they are no longer “flavor of the month.” Unsurprisingly, there are pros and cons to using a moveable tunnel, and many cautionary tales. If you are thinking of buying a slideable/dragable tunnel, and especially if you are thinking of designing and building your own hardware, read this article first! Save money and tears! Like many people, I was intrigued by the idea of having a hoophouse that could have a summer home and a winter home. But after some reading and reflection, I’ve come down on the side of staying put, for us. We value a draft-free winter hoophouse (moveable ones can be hard to close up well.) I have been nervous enough when we have high winds – I don’t want to add to that uncertainty. And we have a crop rotation worked out that suits us. We gradually replace the winter and early spring greens with early tomatoes, peppers, squash. Our climate is warm enough that we don’t need it to grow these crops in the hoophouse in the height of summer – they do fine outside. Growers in colder climate zones like to use their tunnels for nightshades and cucurbits all summer, which can make crop rotation difficult. I can see the benefit they get from a moveable house. In high summer we grow a bean seed crop, which helps our rotation, improves the soil and pays its way. We do use a big sheet of shade cloth over the top when it’s hot.

We cover our hoophouse from mid-May to mid-September with shadecloth. Photo Kathryn Simmons

We cover our hoophouse from mid-May to mid-September with shadecloth.
Photo Kathryn Simmons

Linda Hepler Beaty writes about adding a “WOW factor” to farmers market booths. Gretel Adams provides new information about growing lisianthus, a popular topic she has covered before. Theirs are grown in a hoophouse, using horizontal netting to keep the stems upright.


The Organic Broadcaster for May/June has been out (but I’ve been too busy to read it. . . ) it includes articles about industrial hemp farming, sprouted fodder grains, working on the National Organic Standards Board, transitioning to Organic, assessing the financial wisdom of buying machinery, the impact of warm season grasses on organic dairy cows, farming for wildlife with hedgerows (including elderberry and currants), a review of Lisa Kivirist’s book about women farmers Soil Sisters, farm safety for children, and there is the usual round up  of organic field days and events, news briefs, and classified ads. The 20 pages are packed!

Lisa Kivirist and her newest book. See this site for details of an August Soil Sisters event in Wisconsin.

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