Winter always seems too long, especially for a vegetable gardener. During the garden’s winter down-time you have probably (or should have at least) planned the next growing season, decided what you want to grow, ordered your seeds as you leaf through all the seed catalogs, guestimate how long each plant takes to mature, and determine when to start planting in your garden. You also need to know when to plant “starts” in the house or greenhouse.
There are some plants that are way better off being started right outside, like potatoes, beans, peas, corn, carrots, and other root vegetables. They do not transplant well and if they do survive transplanting they will probably not grow as well as if they had been planted directly in the soil in the first place.
Items you will need to start plants in the house: a sunny south-facing window or grow lights, growing medium and containers, heat mat, seeds, and water.
Getting the timing right for house grown veggie starts can be tricky. Some plants germinate quickly, some more slowly, like some herbs and pepper plants that can take up to 20 days or more to sprout; lettuce, tomatoes, and cole crops (brassicas) all take about a week to emerge from the soil.
Once you plant the seeds in a starter growing medium they need warmth in order to germinate, no light is needed until they pop up out of the soil, just warmth; 70 to 80 degrees F, if your house tends to be cold then a heat mat works well.
Peppers need to be started in the house 8-10 weeks before your last frost date, but this year I started mine on New Years Day. It’s April 1st, and they are all about 5” tall right now. Peppers are slow growers and I need a lot of pepper plants that can produce well for us this year, I have a lot of plans for canning peppers this season. We live in a short growing area, Zone 5b, and getting a big jump on pepper production is key. Our pepper starts will not get planted outside until Memorial Day. FYI, peppers are perennials and can be grown year-round, for several years in warmer climates, and dug-up and brought into the house for the winter in areas that get below freezing.
Tomato plants should be planted 6-8 weeks before last frost, they are easily killed by frost, so don’t plant them outside too early unless you have a way to keep the tender plants from freezing. Tomato plants will get “leggy” (grow too tall because they are reaching for the light) if grown in a window, a grow light will help with this. Don’t worry too much if your tomatoes get leggy, with tomatoes (but not all vegetables) you can burying the stem deeper in the soil when you transplant them, they will just grow more roots.
Cole crops like cabbage, broccoli, and cauliflower, as well as lettuce and onions, can all take a bit of frost without damage. They can be transplanted outside as soon as your soil can be worked. In my 5b area this means I can plant these types of starts as soon as my soil thaws out, so I have started my brassicas indoors the first couple weeks of March. They will be ready to transplant outside mid-April. At this point I will also direct sow my peas, cilantro and potatoes outside as long as the soil is not too soggy. If we are expecting a killing frost I will cover the plants with either a greenhouse cover and/or a thick blanket just as added assurance of their survival.
Squash plants (i.e., cucumbers, pumpkins, melons, zucchini, and all other squash type plants) grow quickly, but cannot tolerate frost, so start them 4 weeks before transplanting them outside. I have found that if I have started them inside and transplanted them outside, or just seeded them right in the soil, there really isn’t much difference in production or yield. The only benefit of starting them inside is that I can better control squash bug and vine borer damage. If you cover the stem of the squash plants where it comes out of the soil, with tin foil, that will often stop vine borer bugs from eating their way into the stalks of your plants. Squash bugs come out at the beginning of summer, so if you start your plants in the house and transplant them outside after the squash bugs have been on the hunt for new plants to attack, you may just have better luck with your plants. Squash bugs will lay their eggs on the underside of the squash plant’s leaves, so be on the continued look out for egg clusters and if you see any remove and destroy them. Do not use insecticide, because if you do your plants will not get pollinated, you will have killed off the good bugs along with the bad ones.
A few more notes about growing seedlings in the house:
· Plant “starting medium” does not have the nutrients that plants need to grow. Starter medium is used to germinate the seeds, once the plants have a set of true leaves the seed cotyledon will no longer provide the feed for growth, the roots take over at that point. You will either need to transplant your seedlings to the garden or to a larger container (solo cups work well as long as you poke drain holes in the bottom) with the proper growing soil or provide the proper nutrients formulated for that plant.
· Always try to water from the bottom, too much moisture on the soil can promote damping off, a disease that causes the seedling to die and rot at soil level.
· Provide good air flow.
· Before planting the seedlings outside, they need to be acclimated to the weather outside, so you have to gradually introduce the plants to their new environment, this is called Hardening off.
· If you are not ready to plant outside yet and the plants are getting too big, you may have to replant into another larger container, you might have to do this several times.
· Only allow one seed per growing cell, gently pull out or cut excess seedlings. However, onion starts can be grown with multiple plants per cell because you will separate them when you go to plant them outside.
Fungus gnats and aphids can be a huge problem with indoor plants; if you see any flying around the house kill them, vacuum them up, set traps, get or make yellow sticky traps as soon as you see them, they multiply exponentially every day.