Transplanting vs. Direct-Seeding and The Heijunka Calendar

The Heijunka Calendar can help you to plan a vegetable garden and make your planting more efficient by rotating vegetables throughout the season.

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The Lean Farm Guide to Growing Vegetables (Chelsea Green, 2017) by Ben Hartmanshows how to save yourself time with the lean farming method. The Heijunka Calendar can help you to plan a vegetable garden. Hartman teaches readers to plant more efficiently by rotating vegetables throughout the season. Follow the instructions Hartman provides to cut down on time spent in the garden. He targets market vegetable gardeners to help farms increase profit and decrease waste. This excerpt can be found in Chapter 5, “Transplanting by Hand.” 

Transplanting by Hand

When we started farming, we direct-seeded nearly all of our crops into the ground rather than using transplants from a seedling greenhouse, because it was faster. When you can plant thousands of seeds in a matter of minutes, we thought, why bother with seedlings?

But this was shortsighted thinking. Seeds failed to germinate when the soil dried out in hot sun, or they became waterlogged after a rain. If they did germinate, weeds often smothered them. Much was left to chance; defect costs were high.

When we started to implement lean, we realized that to reach our goal of 100 percent success — of every seed turning into cash — we could not tolerate those costs. By using transplants, we can be certain seeds will germinate and that crops will go into the ground weeks ahead of the appearance of weeds. Also, with transplanting we can space crops perfectly, saving costly time spent thinning. While we still direct-seed a few crops when the weather is just right, most of the time we now rely on transplanting. We have developed methods to transplant turnips, radishes, baby greens, green beans, and other crops that many farmers only direct-seed.

The key to successful transplanting is efficient motion. Transplanting requires a lot of movements: bending over, poking holes in the ground, and watering plants in. This work might be tedious, but it should not be mindless. It is critical when transplanting to analyze every step and find ways to simplify and eliminate waste.

Simpler Crop Spacing

In our quest for the simplest possible system, we transplant almost all of our crops either 6 inches or 10 inches apart. To mark rows we slip 6-inch PEX plumbing tubes over bed-rake tines, leaving six tines (about 10 inches) between tubes. Walking one end of the bed to the other, we mark the beds by dragging the tubes along the ground, and then we mark rows across the bed, creating a grid. For 10-inch spacing, plugs go in at every crossing point; for 7-inch spacing a plug goes in at every crossing point plus in the middle between crossing points. For crops planted at just one or two rows per bed, we do not use this system. Instead we find it more efficient to mark 6-foot stakes that we lay on the ground beside us as we work, putting in plants at each marking.

Multiplant Plugs

While we usually use paper pots now for large-scale transplanting, it is helpful to see our hand-transplanting method, too, which we use for smaller planting. For most hand-transplanted crops, we seed one seed per cell. However, we use multiseeding — putting several seeds in one cell — with crops that can tolerate closer spacings. This eliminates moves at transplanting time, cuts down on space in the propagation house, and allows us to transplant crops that otherwise are typically direct-seeded. Examples include the following:

Turnips. We seed Hakurei turnips into 72-cell flats and transplant them three rows to a 30-inch bed, 10 inches apart, after about four or five weeks, just after true leaf stage but before roots bind up in the cells. We drop a pinch of seeds, aiming for four to six, in each cell. That requires very little cultivating later, because the crop is far ahead of the weeds. The roots grow away from one another and eventually reach full size. At harvesttime we sometimes pull entire clusters; other times we choose the largest turnips from several clusters, leaving others to grow.

Radishes. We direct-seed radishes when conditions are just right, but for an early crop we seed them in 72-cell flats at four to six seeds per cell, and transplant them at five rows per bed, with 7 inches between plugs. The primary advantage with multi- seeded radishes is that we are able to supply radishes much earlier in the year. In January and February we let them grow for around three weeks before transplanting to a hoophouse or greenhouse, where they take off quickly.

Peas. For an early stand of peas we use 50-cell flats and drop four seeds in each divot. We germinate them in a 68 degree germination chamber. We transplant when the peas are 3 to 4 inches tall. We transplant them in one row for ease of trellising at a spacing of 4 to 6 inches between plugs.

Mizuna. For faster mizuna in the midwinter greenhouse, we transplant plugs rather than direct-seeding. The mizuna grows for two to three weeks under grow lights in our basement before being transplanted out. We use 72-cell flats with four to six seeds per cell. We space them 7 inches apart, using five rows per 30-inch bed.

Spinach. As with mizuna, we prefer to transplant midwinter spinach to shorten seed-to-harvest time. We use 72-cell flats and seed four to six seeds in each cell, and transplant in five rows, leaving 7 inches between plants.

The Heijunka Calendar

The Heijunka Calendar tells us when to seed each crop, based on our orders. The Kanban Map tells us how much to seed.

An approximate English translation of heijunka is “load leveling.” According to lean, when work is spread out and evenly paced, quality increases. When it is crammed and rushed, quality suffers. A key objective of our Heijunka Calendar is to help us level stress points. One of the stress points for us in the early years of our farm was midsummer. Spring planting had worn us out and yet there was no time for a break. Our mistakes escalated. Now we plan for a vacation every July. We stop our CSA and wholesale deliveries for a few weeks and limit what we offer at the farmers’ market to an amount that an intern and perhaps a hired helper can handle.

Another goal of the Heijunka Calendar is to simplify planning. With the calendar, our entire year fits onto one or two pages. We post the calendar in the processing area and in the seedling greenhouse for ready access.

The calendar is arranged weekly. Crops can be planted anytime during the week. DS means crops are direct-seeded. Otherwise, crops are seeded into flats or paper pot chains in the greenhouse for transplanting to the field. To alleviate stress points, we shift seeding dates around — for example, seeding more in February and less in May.

How do we determine the number of seeds to plant? We refer to the Kanban Maps to determine the number of beds we want of the crop. Then we calculate the number of plants per bed. For example, let’s say it is the first week of February. Our Heijunka Calendar tells us it is time to seed kale for an unheated greenhouse. Our Kanban Map shows that we want three beds of kale. So we will plant the proper number of seeds into a plug flat (or a bit more to cover possible seedling losses). The system is simple enough for anyone to follow.

Our basic farm plan is to start tomatoes for heated greenhouses in the last week of January. A week later we seed quick crops for interplanting between the tomato rows–head lettuce, baby greens, romaine, beets, turnips, radishes, and green onions — all as transplants. This gives us a full selection of food by late March — when most farms are just gearing up–and takes advantage of precious heated greenhouse space. After we harvest the quick crops, the tomatoes fill in the open spaces. Fall planting also begins early–the last week of May with storage carrots–and continues June through September with kale, beets, turnips, radishes, and greens. This long season gives us a wide selection of fresh crops going into late fall, when other farms are packing up for the year. We call this farming the shoulders because it focuses our production on the shoulder seasons when demand is highest — and gives us that July vacation.


Ben Hartman grew up on a corn and soybean farm in Indiana and graduated college with degrees in English and philosophy. Ben and his wife, Rachel Hershberger, own and operate Clay Bottom Farm in Goshen, Indiana, where they make their living growing and selling specialty crops on less than one acre. Their food is sold locally to restaurants and cafeterias, at a farmers market, and through a community-supported-agriculture (CSA) program. The farm has twice won Edible Michiana’s Reader’s Choice award. The Lean Farm, Ben’s first book, won the Shingo Institute’s prestigious Research and Professional Publication Award. In 2017, Ben was named one of fifty emerging green leaders in the United States by Grist.

The excerpt is adapted from Ben Hartman’s book The Lean Farm Guide to Growing Vegetables: More In-Depth Lean Techniques for Efficient Organic Production (Chelsea Green, 2017) and is reprinted with permission from the publisher.