Winter is the perfect time to get a head start on spring planting. Of course, you can purchase starts from garden centers, but seasoned gardeners know the really spectacular varieties simply cannot be found anywhere but in seed catalogs and must be grown indoors for some weeks. Starting your own seedlings offers more range and is less expensive, and watching your garden grow from seed is priceless. Here are a few tips to germinate and grow like a pro.
Keep Your Seeds Fresh
While market-gardeners might use entire seed packets in a season, most home-gardeners never come close. Store your leftover seed packets inside an airtight jar in the refrigerator, preferably with a cheesecloth-wrapped bit of powdered milk in the bottom to absorb moisture. Flower seeds usually stay viable for one to three years; vegetables can last two to four. Replace your seeds within those windows to ensure high germination rates.
Start Your Seeds at Just the Right Time
Remember, it’s best to start seedlings indoors to get a jump on plant development in regions with short growing periods, but no need to start too early. In fact, planting too early can backfire. Wait until six weeks before your last frost date to start most seeds. If you aren’t sure, use a planting calendar tool to help.
Use a Seed-Starting Mix
The best seedling mix is one you make yourself: combine equal parts peat moss, vermiculite, and perlite. If you need a smaller volume, pre-formed seed starters can be quite useful. Don’t re-use potting soil- especially if you’re planting herbs. It may be too coarse for your seedlings’ delicate roots, and it may be contaminated with fungal spores or other unwanted nasties.
Use Clean Containers
Any clean container with drainage is acceptable, but products designed specifically for starting seedlings are better suited to your needs. If you prefer not to use plastic, you can buy biodegradable pots that are planted directly in the garden without disrupting your seedlings’ delicate roots. Make sure your containers are set in a tray a few inches deep.
Get Temperature, Moisture, and Monitoring Right
Pre-moisten your mix evenly, so it’s moist but not wet before sowing seeds. Follow the instructions on seed packets to ensure you plant at the right depth, and use something like a chopstick to push seeds into the starting mix. Many people choose to cover their seed trays loosely with plastic or a cover to retain moisture but make sure there is still some air circulating.
When the soil is ten degrees warmer than the air temperature plants stand a better chance of germinating. You can buy special electric mats to place under your seedling trays or place seedling trays on the top of your refrigerator to take advantage of the appliance’s heat.
Check on your seed starts often, and as soon as they begin to sprout, remove the cover so that they can breathe. Water your trays so that the pots are watered from the bottom to establish strong root growth, and don’t overwater.
Potting up and Hardening Off
If you’ve started your seeds in seedling flats with small cells, you’ll want to transplant once the plants get their second set of leaves. If you began with multiple seeds in single biodegradable pots, you should select the strongest and pinch out the others. If you keep your seedlings in a window, make sure you rotate them every other day for even growth.
Once the risk of frost has passed and it’s almost time to transfer your seedlings to the garden, you must prepare your babies for the harsh realities of outdoor living. Water less often the week before moving them and don’t fertilize. A week or so before they’re scheduled to go in the ground, place them outside in a protected area out of direct sunlight. Keep their soil moist during this adjustment period, and transplant them into the garden early in the morning or on an overcast day to help minimize shock.
The magic of watching tiny seeds grow into a glorious garden can be rewarding. If you’re a first-time planter, this guide should give you the push you need to dig in.
Carrie Shaker is a landscape architect and mother who enjoys working on outdoor DIY projects with her children.