Tomato Starts–A Farmer’s Guide

We don’t do much bible quoting around our farm, but there’s an old biblical admonition, “don’t hide your light under a bushel basket”,  that seems pretty apt when it comes to tomato starts.

Every year, our starts seem to outperform those big, bushy plants you find at  commercial outlets like nurseries, Big Box stores and supermarkets. Sometimes ours don’t look as robust as theirs do on the shelf, but as the season progresses their plants’ vigor often wains, and by harvest time a lot have died or are duds, while ours are bearing nicely.

How do we do it? Persephone’s Farmer-in-chief, Rebecca, explains in this guest post on starting your tomatoes.



“Not long ago, we visited a wholesale nursery operation. They had some super tomato varieties that I knew were delicious because I had tasted them in my mom’s garden back in southeast Pennsylvania, years ago. But when I moved here to western Washington and tried to grow them, they just wouldn’t ripen or produce fruit.

“The problem was that those tomato varieties love the hot, humid summer weather we had back in Pennsylvania, but out here we live in a sub-par tomato-growing environment where most varieties don’t thrive. That made me think: what a disappointment for all those people who will buy those starts, expecting wonderful, delicious tomatoes later this year.

wilted tomato

“The Lesson: It is important to stick with tomato varieties that are tried and true producers in your growing area, that will come through again and again, not ones that have nice descriptions on their shelf tags but will never work in this environment.

“We raise lots of tomatoes, both from heirloom seeds we save ourselves and from seeds we buy from commercial suppliers. But they are all well adapted to our long, cool, summer days.  Over years of doing this, we have found that these varities will set fruit, ripen well and produce a decent yield.

“The tomatoes we prefer, with some notable exceptions, tend to have smaller fruits. Cherry tomatoes, in general, are very reliable, heavy producers. Stupice, which is an heirloom variety, is one of our favorites, along with Glacier and Early Girl.  We’ve also had success with Cherokee Purple, Prudence Purple, Moskvich and Jaune Flamme.

Stupice Tomato

“When you go to a commercial nursery or plant outlet at this time of year you are likely to see tomato starts with a lush foliage canopy. That’s because they are usually fed commercial liquid fertilizers. We make our own potting mix, which has more vitality than theirs. The whole concept of organic production is that the soil feeds the plant. That sounds obvious, but the concept behind industrial, chemical farming is that the soil is just the substrate to hold up the plant, then you supplement its diet with an array of fertilizers and liquid fertilizers.

“Making your own potting mix is labor intensive, but we think it yields far superior plants. Our starts usually look smaller than the nursery varieties, but they’re more stocky and hardy. And if you take them out of their little four-inch pots you’ll see they have dense root systems. Other plants I’ve seen for sale that are taller and more lush above ground don’t have similar root systems, which is why they don’t hold up through the growing season.

“So, to briefly recap, we grow well-adapted varieties, starting them indoors in late February, and using a sterile, soil-less mix we make with ingredients such as peat, perlite, vermiculite and coir, which is a coconut husk fiber. We plant our seeds at a depth of about three times the seed’s diameter–quite shallow–and try to keep them at about 70-degrees, day and night. To do that, we use heating coils you can buy at any garden shop.

“In five-to-ten days the plant should be pushing up through the soil. Within a month or six weeks of growth–when they are about two inches tall and have little leaves–we move them from their flats to the four-inch pots. A lot of the timing depends on the weather and the available daylight. Again, when we do this transplanting we make the potting mix, blending inert materials  like peat, coir or perlite, and some of our own soil, compost, worm castings and other good stuff. But you can use a commercial potting mix instead.

“About six weeks later, we begin to harden them off, moving them outside for a week or two, depending on weather and light.

hardening off tomatoes

“The key is to be patient and wait till the weather stabilizes at a reliable 50 to 60 degrees during the day and there is no danger of frost at night. We generally wait until mid-May to plant outside.

“When we are comfortable with the weather, we take the plant out of its pot and shake out the roots. Then we make a depression in the soil (or in a pot or hanging basket,) and add some organic fertilizer and a little water.

“Tomatoes have a unique ability to grow roots out of their stem, so if you plant them deeper they will have more root structure. Try snapping off the plant’s bottom leaves–using your fingers, not scissors–to plant a bit deeper. You don’t need to do this, but it encourages the plant to grow more roots to get additional water and nutrients.

“During transplanting into the field, we use a complete organic fertilizer–that is, a fertilizer that doesn’t have too much nitrogen, but has decent amounts of potassium, phosphorous and calcium.

“We don’t recommend using manure to fertilize at this stage because it may be too nitrogen-rich for the plants. That will cause excessive leafing at the expense of fruit yield.

“One last tip: Growing tomato plants in containers makes sense, especially for the casual gardener. Try to find a place in a warm environment, close to the house if possible to get reflected sunlight off a south-facing wall. That way they will also be easier to water and pick when they ripen. If you live on the shore, sunlight reflecting off the water can make a big difference.

“The important thing is to remember to choose a warm spot with all-day sun for your tomatoes. If you can’t find such a spot you might consider planting cherry tomatoes, which will work better in partial shade.

“And you don’t need to stake or trellis your tomatoes at this stage. That will come later.

“Last summer was the best tomato-growing weather in 15 years–lots of early season sunshine and warmth all the way through the summer. We’re crossing our fingers for more of the same this year.

“If you have questions about transplanting your tomato starts, send us a comment and we’ll try to get an answer for you.”