Get Your Seedlings Off to a Great Start

Starting your own plants from seed is lots of fun and very rewarding. But the truth is that it can also be confusing and a little intimidating! Here are a few tips to help make sure your experience is a good one.

Some seeds are easier to start than others

It’s easy to be seduced by photos in the seed catalogs – it happens to the best of us, especially in January. But what the catalogs don’t tell you is that some plants are much harder to start from seed than others. No matter how much seed-starting experience you have, starting tomatoes is easier than starting primroses. This is because some seeds will germinate almost anywhere, while others have strict requirements for moisture, temperature, and light.

So if you’re new to seed-starting, I recommend that you stick with some easy varieties such as tomatoes, zinnias, marigolds, peppers, and coleus. These seeds don’t have any special requirements in terms of light, moisture or pre-treatment.

Most seed packets provide little if any information as to specific germination requirements. I am a big fan of Stokes Seeds in Buffalo, NY because their seed packets are written for commercial growers and provide lots of useful details. When you’re growing a challenging type of plant such as primroses, the information they provide is invaluable.

If you plan to grow lots of flowers, consider picking up a copy of From Seed to Bloom, by Eileen Powell. It provides specific germination requirements, growth habit, time of bloom, and much more for over 500 different kinds of flowers and herbs.

Containers are a personal choice

Catalogs offer different seed-starting trays. How do you decide which kind to use? I recommend experimenting with several. Ultimately you’ll choose one kind over another based on things like how much room you have, how attentive you are with watering, what kind of plants you’re starting, how long the plants will be in the containers, and how many transplants you’re growing.

Over the years I have settled on four different seed-starting systems. I start very tiny seeds (like snapdragons, violas and oregano), and seeds that take a long time to germinate (like primroses and larkspur) in 4″ x7″ peat flats. I sprinkle the seeds on the soil surface and cover with a sprinkling of soil (unless they require light to germinate). Then I put four to six peat flats into a standard 10″ x 20″ tray and cover the tray with a clear plastic lid to keep moisture levels constant. Once the seedlings have their second set of true leaves, I separate the individual plants and put them into their own growing cells. This system is quick (my own #1 priority) and really saves on space. I transplant only as many seedlings as I need, and there are no bare cells where seeds didn’t germinate.

I also use a standard 10″ x 20″ plastic tray with a 36 cell insert and a clear plastic lid. One nice feature of this system is that you can separate the insert trays into six-packs. This is makes it easy to share extra seedlings with friends. I use this system for annual flowers such as zinnias, marigolds and impatiens.

I am also a big fan of PaperPots. For starting a large number of seedlings of one variety, they simply can’t be beat. I use the large ones for tomatoes, peppers, and eggplants (transplanting them other smaller containers once the plants have their second set of true leaves). I use the medium size for sowing annual flowers – especially varieties I’m growing in quantity for the cutting garden. The medium size pots also make a great second home for seedlings that I’ve started in the peat flats. PaperPots retain moisture very effectively, and you can grow 80 plants in about two square feet!

I’m always cramped for space, so I reserve the Accelerated Propagation System (APS) for special varieties that really benefit from extra TLC. I find peppers, which can be finicky about moisture, always do well in the APS. I also use them for impatiens, asters and parsley. And I usually start my tomatoes in an APS, then transplant them into PaperPots. If you’re new to seed-starting, the APS is a pretty foolproof system.

After you’ve planted your seeds, I recommend that you cover the container with plastic wrap or a clear plastic lid. As soon as the sprouts have come up through the soil surface, remove the lid or plastic wrap so your seedlings get the maximum amount of light and plenty of good air circulation.

The right soil makes a difference

Regular garden soil or potting soil is too dense for the roots of tiny seedlings. A good seed starting mix will be a soil-less mixture of sphagnum peat moss, vermiculite and perlite. This blend will hold moisture, but also be light enough to provide air and wiggle room for the seedlings’ roots.

All soil-less mixes should be thoroughly moistened before you put them into the flats or containers. Dump some of the mix into an old dish pan, add warm water, and mix it around with your hands until the moisture content is that of a well-wrung sponge. Then fill your containers. Sow your seeds and gently press them into contact with the soil. You don’t want air pockets, but you also do not want to compress the medium any more than necessary. Water thoroughly with a gentle dribble so you don’t disturb the seeds. This initial watering is important to establish good contact between seed and soil.

Nurseries offer soil-less seed starting mediums. Professional Germinating Mix has the finest texture. It is my first choice for starting seeds and is a must for use in the APS system. Transplant Mix has a coarser texture and is best for larger seeds such as cucumbers or sunflowers, or for transplanting tiny seedlings into larger cells or pots. Compost-Plus Germinating Mix is Transplant Mix that has been fortified with compost and other organic nutrients. All of these mixes contain some nutrients, but you’ll still need to fertilize your seedlings once they have their second set of true leaves. I use TPH for seedlings, which contains both organic and readily-available inorganic nutrients. I alternate that with a seaweed fertilizer, because I’m convinced it gives me sturdier, more stress-resistant transplants.

Searching for Seeds

The seed catalog has been around almost as long as the printing press, it seems. There were thousands of seed companies to serve both farmers and housewives in the 1800s, and several of the familiar names we purchase from today have been in business since then. Seeds are easy to package and ship, they last a long time compared to live plants, and are inexpensive to send through the mail.

Most seed companies combine annual flowers and vegetables, but some specialize in vegetable seeds only. You’re generally safe buying almost anything out of almost any seed catalog, as long as you’re a savvy gardener and careful to order things that grow well in your region.

When comparison shopping, get out a pad of paper and note items like seed count per packet and price. There’s a surprising amount of variation in these two factors between companies. One catalog may list ‘Watercolor’ pansies at only $1.49 per packet, but they give you just 25 seeds. The smart buy is the $2.49 packet that gives you 100 seeds, and those $1 differences add up quickly if you’re making a large order (or several orders to different companies).

It’s rare to have a real problem with mail-order seeds, but sometimes damaged orders or very poor germination do occur. This is the point at which customer service suddenly becomes very important.

Once, I ordered petunia seeds from two different major seed houses. One packet germinated great, and I knew the company would have offered credit toward my next order if I had a problem. Out of the other packet, only one sad little seed germinated, and in response to my dissatisfaction with their seed quality, they just sent another packet of the same seeds. Naturally, I was less than thrilled, and have not shopped from that catalog since.

The type of packet seeds are shipped in can be important as well. Some use plain paper envelopes, some use vacuum-sealed foil, and others use a combination, especially when the seeds are very tiny and require an inner envelope so you don’t lose them. Foil can keep the seeds fresher in storage, especially if you don’t use them all at once and want to keep some for later. But as long as you plan on using the majority of the seeds right away, paper packets work just fine for most varieties.

May 22, 2011 · admin · No Comments
Posted in: Gardening