The Island Garden
It's that time of year again, time to think about starting your seeds. If you assume that May 15 is planting out day, six to eight weeks before that you should start your tomato, pepper, eggplant, leeks, onions, and many other seeds. However, I have found that leeks and onions can be started right now. Peppers and eggplants often take a while to germinate so I start them early too. However, do not start your seeds too early. If you start them now and do not have a greenhouse to put them in, you'll be tempted to put them out too early and if we get a sharp late frost, you could lose everything.
If you are an optimist or live farther inland, you can assume that May 1 is a good planting out day and start your seeds around the middle of March. But first you'll need to lay in some seed starting supplies. You'll need seed trays. I use the 11- by 22- by 2-inch deep trays that Jamestown Hardware has in stock. In my opinion you don't need the clear plastic covers for seed trays, simply use some plastic wrap for the five to seven days that seeds need to germinate. You can also buy inserts for these trays to enable you to set seeds in individual pots. I prefer the insert that has 48 or 64 individual cells per tray. This allows me to get individual plantlets ready to be potted up into larger pots without damaging roots of plants that may be tangled together in a seed tray. You can also use peat trays which simply get buried right in the ground. Another method is to make paper tubes from old newspapers and start your seeds in them. These too can be planted directly into the ground. I've also seen egg containers, juice boxes and other small cartons used as seed trays.
You'll also need potting soil. I prefer to use ProMix, which is a professional mix used by commercial growers. I find that I go through one- to-one and a half three cubicyard bales each season. However, if you are starting only a few seeds you can buy a bag or three of potting soil at Jamestown Hardware store. When you buy potting soil (there are many different mixes) look for one that has a good proportion of soil, compost, perlite and a little sand. I prefer a lighter mix that absorbs water easily. I'm not a fan of mixes that contain water retaining gels and fertilizers. Fertilizers tend to be used up fairly quickly as you water the soil and don't help plants germinate.
You'll also need a nice warm spot where temperatures stay around 65 to 75 degrees. Most seeds like it warm to germinate, and cooler to grow. Another item you will probably need is a roll of plastic wrap such as Saran Wrap. Use this to cover the seed trays until the seeds have germinated. You'll also need seeds. You can get them by mail order or if you look around carefully, some stores are already selling them at a discount.
So now you are ready to start seeds. First, pay attention to your potting soil. It should be moist, but not too wet. I wet out my potting mix with warm water to make it nicer to handle and to give the seeds a quick warming boost. The mix can be tested by squeezing it in your fist. If you can squeeze moisture out of it, it's too wet. Lay it in your potting trays or individual cell trays. Tamp it down well so that it is firm, but not compressed. Sprinkle your seeds onto the surface, spacing them carefully. If you have individual cells put one seed in each cell. Remember that some seeds such as primula and impatiens require up to 20 hours of light each day, so don't cover them with more soil. Read the instructions on the seed packet to find out how much light is required. Most seeds need more than 12 hours each day to germinate. For most seeds you should sprinkle a little more potting soil over them to cover them to about the thickness of two seeds. In other words, larger seeds are covered to a greater depth than small seeds. Finally, use a spray bottle and lightly wet the surface of the potting mix, then cover with a piece of plastic wrap.
I put my seed trays in a specially made germination chamber with shop lights, each with a cool white and a warm white fluorescent light bulb in them. By using a cool and a warm light in each fixture you cover most of the growing spectrum. If you use only a warm white, it tends to the red end of the spectrum which helps to promote flowering rather than growth. The lights are placed two to three inches above the seed trays and raised as the plants grow so that the plants never actually touch the lights (except when I forget to raise them).
In five to seven days expect to see some germination if you have kept temperatures around 70 degrees. Lower temperatures take longer to germinate. Remove the plastic wrap, set your growing lights on 12- to 14- hours per day and water every other day or so. Your plants should grow quickly and easily. After the plants have a pair of true leaves, you should pot them up into larger pots and move them to your greenhouse. This should occur around early April. A month in the greenhouse will give you nice stocky plants ready to be planted out in early May.