Vegetables Not To Start Indoors . . .
. . . and why (plus how) to raise these plants indoors anyway.
Your friendly, impatient Planet Natural Blogger has a hard time waiting for the ideal time to start seeds, especially those that do best when directly sown in the garden. We’ve all heard how some vegetables shouldn’t be started indoors. Peas, beans, corn, and most definitely root vegetables (carrots, beets, turnips, and the like) do best planted right in the ground where you want them to grow. Starting them indoors can be a frustrating waste of time. And for different reasons.
Peas and bean germinate and grow well indoors. But transplanting sets them back. Plant some peas in your garden on the same day you transplant the peas you started indoors and within a month or less, the direct-sown peas have caught up with, even overtaken, the transplanted peas. Same with beans. Corn started in containers indoors often grows, leggy, doesn’t develop the strong root ball that it takes to good, well-anchored transplanting, and needs several days to harden off.
Root vegetables present a different problem. Their roots develop quickly in length, then add bulk as the season goes on. Starting them in cells, pots, or other containers can inhibit that quick root length growth. And those roots are easily damaged when transplanted. The few times we’ve tried to transplant carrot starts resulted in weirdly twisted carrot shapes. Remind us to tell you about the time we grew a three-legged carrot!
So we’ll concede the point on most root vegetables, except maybe onions. But there are advantages to starting peas, beans, and corn indoors, depending where you live and when your soil temperatures warm adequately for germination. If you’re fortunate to have a long growing season and warm spring soil temperatures then by all means, plant your peas and beans directly in the garden. If, like us, you live where winter lingers well into spring (and even summer!) and need a jump start — or maybe you’ve lost pea and bean seed and shoots to crows or other pesky creatures on the wing — then here are ways to get a jump on growing.
Peas, unlike those you stick in the ground before the soil temperature has warmed to 45 – 50 degrees, will germinate quickly indoors, especially when started on a heating mat, on top of a refrigerator, or other warm spot (but not too warm, like a radiator; pea germination drops off above 80 degrees and seeds won’t germinate at all if the soil temperature is over 82 degrees — 60 – 65 degrees is ideal). Inoculate seeds before planting just as you would outdoors.
In ideal conditions, your peas may germinate in as few as four or five days. Let them grow until they carry at least two true sets of leaves, then transplant. If conditions outside don’t merit transplanting and you need some time, let the pea shoots develop four or five sets of leaves, then, a couple-three days before transplanting, pinch off the top few leaves. This will slow root growth and encourage a denser, fuller plant. Indoor lighting is a great boon to starting peas indoors.
You’ll want that stronger stem when it comes time to set out your plants. Harden them off in a cold frame if you have one. Makes sure the delicate shoots are protected from the wind.
When transplanting, the goal is not to disturb the roots as best you can. If your container isn’t big enough and your peas are already root bound, well, then, abandon all hope. But, since we knew better, moisten the pot so that the soil slides out easily. Do it like my grandfather taught me. Slide you fingers scissors-like at the base of the stem, then turn the pot, plant and all, upside down. Your fingers and palm will support the soil as is. Cup the bootom of the soil with your other hand before turning it over an putting it in the hole you’ve prepared.
Important: plant your peas to the exact depth they were growing in their starting pot. Don’t heap extra soil around the stem. It will encourage rot and late damping off. To avoid further disturbing the roots, have you pea trellis or other support in place before transplanting.
All the above pea practice applies to beans as well.
Where we live in Montana, winter can hold tight well into May. Then you wake up one day and its summer. Why aren’t your peas in the ground? If you can see that rapid change coming a few days in advance, you can give your peas a head start by germinating them indoors first between damp paper towels and then (very carefully) placing the new sprouts in drill holes in your garden. The method for doing this is familiar to every school kid. Here’s detailed directions.
Same method works for beans. Plants seeds a day or two after sprouting. Don’t let them develop a long tap root or true leaves. Plant them in the garden at the same depth you would plant unsprouted seed, roughly one inch.
Corn is actually a good choice for starting indoors, especially for varieties that need warm soil temperatures to germinate. And if you’re setting out hardy plants come warm weather, the crows and other seed and sprout pickers will probably ignore them.
Corn presents a different set of problems than do peas and beans. It’s root ball spreads wide and isn’t so deep. So make sure you use a pot with a sizable width. Starting plugs and grow cubes work but be sure to transplant before roots start emerging from the sides of the plug. Using indoor lights is especially beneficial to corn. It promotes strong growth and prevent legginess. Keep the light close — six inches — to the top of the plants. Lights will keep your corn from growing so tall in the pot that it has trouble staying upright when transplanted outdoors.
Growing to the right size can be a fine balancing act. And even if the corn you sow directly in the garden eventually catches up to the corn you’ve started indoors, don’t be discouraged. We’ve had years, especially in the cloudy Northwest, where the only corn we harvested came from plants started outdoors. And, starting those seeds indoors gave us something to do — other than thumb twiddling — while we were waiting for acceptable outdoor growing conditions.
To what extent will people go to start vegetables indoors that will survive transplanting? Check out this thread and look for the guy who starts seed inside lengths of PVC pipe, then plants the whole thing, pipe and all, in the garden (scroll down to photo). No root disturbance there. Let us know your experience and what techniques you use to start these difficult seeds — beans, peas, corn, even root vegetables — indoors; here or on Facebook. We always have more to learn.