Seed Starting Basics
Winter is a fun time of year for gardeners. We get to browse seed catalogs and web sites and dream of bountiful gardens with never a thought for inconvenient truths like digging or weeding.
But before you actually start buying seeds, take time out for a reality check Ð especially if you are a new gardener. Do you know how much sun your garden will receive through the growing season? Most vegetables and many ornamental flowering plants need at least six hours of full sun daily. Now consider the growing requirements of those seeds youÕre contemplating Ð just how big is your garden, and how much room will those seeds require when they grow into mature plants? Keeping these realities in mind as you decide which seed varieties to buy will help ensure a successful harvest later.
Growing from seed not only gives you a much larger selection of vegetables and flowers to choose from Ð including unusual varieties youÕre unlikely to find at a garden center Ð it also lets you get a jump on the growing season by starting many plants indoors. Generally speaking, annual flowers and vegetables are the easiest to grow, and their seeds germinate quickly.
When to start seeds indoors is a little tricky: Check seed packets for Òdays to germinateÓ and how many weeks growth each variety of seedling needs before being transplanted to the garden, then count backwards from your areaÕs last frost date. (If you donÕt know that date, call your extension service or ask a local nursery.) You donÕt want to start too early, or your seedlings may grow weak and leggy.
To get growing, youÕll need peat pots, pellets, plastic flats, egg cartons with holes poked in the bottom, or other shallow containers with good drainage; growing medium (a special soil-less mix for seeds is best); a plastic humidity cover or plastic bag; plus water, fertilizer, labels, warmth and light. If you re-use plastic pots or flats, make sure they are thoroughly clean Ð a couple of minutes in the microwave should sterilize them Ð before filling them with moistened mix to within _-inch of top. Or use peat pellets, which expand when moistened and can be transplanted intact, without disturbing delicate roots. Whatever containers you use, place them in a waterproof tray so you can add water from the bottom, so seeds arenÕt disturbed. Keep the mix damp, but not soggy.
Plant seeds according to packet directions Ð generally, two or three times as deep as the seedÕs diameter. Seeds that need light to germinate should barely be covered. Label each container with the plant name and variety, and date of sowing, then cover it with a humidity dome or place it in a plastic bag until seeds germinate Ð but allow for air circulation by not sealing the bag. Bottom warmth (75 to 85 degrees F) helps seeds germinate, so set trays on an electric heat mat, or atop a refrigerator or radiator.
Once seeds germinate, they need light. A sunroom or windowsill that gets lots of natural light (with daytime temperatures of 60 to 70 degrees F) might work, but most gardeners will need to put their seedlings under fluorescent or full-spectrum lights for 12 to 16 hours a day. Inexpensive Òshop lightsÓ will work fine. Position the lights immediately above the seedlings, and adjust upwards as the plants grow. When plants have two sets of true leaves, add half-strength liquid fertilizer such as fish emulsion to the watering tray once a week.
Some seedlings may have to be transplanted into larger pots to give them room to grow and develop their root systems. Use the same procedure and mix as for seeds. Handle the baby plants gently by their leaves, not stems or roots, and try to keep the tiny rootballs intact as you move plants to their new pots. Poke a hole in the moistened mix with your finger, place seedlings in the hole, and gently firm mix to eradicate air pockets. Water and fertilize as before, and provide plenty of light and gentle air circulation.
Your young plants need to be hardened-off before you can transplant them into the outdoor garden. That means gradually adjusting them to the outdoors by setting them out in a sheltered, shady spot for a few hours a day. Each day, increase the time and the light exposure. Keep them watered, as small pots will dry out quickly outdoors. After a week to 10 days, plants should be ready to be transplanted into the garden Ð though you may still want to cover them with sheets of newspaper at night if temperatures are particularly cool.