Seeds & Seed-Starting
Buying Seeds
Check out our favorite seed companies here >>>
First of all…
YOU DON’T HAVE TO BUY NEW SEEDS EVERY YEAR!
Most seeds stay viable for at least a few years. The only seeds we buy every year are alliums (onions, leeks, etc), parsnips, and a few herbs (like Angelica). Everything else will be good and growable for several years if you store them well. Good storage means: dry (paper envelopes, indoors), cool (not on top of a radiator), and as air-tight as possible (jars, bins, ziplock bags). Have extra fridge or freezer space, even better.
Find a source that you trust.
We like small, local companies best. Seeds from these businesses tend to be bred for our climate and tend to be healthier than ones that may have come halfway across the world.
General seed terms you may come across:
GMO-free:
What they mean is–the seeds they sell have not been knowingly modified in a lab. Of course, in highly farmed areas, there is some chance of cross-pollination, but it’s not all that likely. All seeds that you as a consumer can purchase are GMO-free. Large producers and farmers can buy GMO seeds; you really won’t have that option, so don’t worry.
Organic:
USDA Organic Certification requires seed growers to use very specific practices. Oddly, certain things are prohibited such as using kitchen waste compost and manure from uncertified animals. We at CT Seedlings get organic seeds sometimes, but they tend to be expensive and we don’t really find them necessary. It’s more important to buy from companies that follow broader sustainable and ecological practices such as using no toxic herbicides, pesticides, or fungicides.
Heirloom:
An open-pollinated variety that has been saved and cultivated for many years (50+ yrs).
Open-pollinated:
A variety that has been cultivated and bred for many plant generations (seed to flower to seed, and repeat) so that each seed grows true to its parents’ genetics. You can save seed from these varieties (assuming they didn’t cross-pollinate) and grow the same variety next year. Most of our varieties are open-pollinated types.
Hybrid (F1):
A “new” variety where if you saved seeds and planted them you may get plants with slightly different genetics. Many hybrids are bred to tolerate diseases, extreme weather, or have an unusual color or shape. Some hybrids are patented by the breeder so you “can’t” legally save seed and grow them again.
Planting Seeds: understanding seed packets...
I'm going to go through a seed packet with you and show you what they're talking about.
Direct Sowing vs. "Start Indoors":
Some plants really don’t like to be moved once they’ve started growing. Carrots are a prime example. Even the experts don’t start their carrots and then transplant them. Carrot roots are notoriously fussy about any damage, jostling or any little obstruction. Therefore, we prepare a lovely seedbed in the garden or a container and plant them right in the ground. There are many other plants that are traditionally direct sown. Peas, beans, squashes, corn, cucumbers, cilantro, radishes, poppies, bachelor’s buttons, borage, and many more. These are all plants that develop a taproot early on and don’t love to be handled. If you are very careful when transplanting or use plantable CowPots (like we do at CT Seedlings), we find they grow just fine!
“Start Indoors” or “Transplant only”: Here in the colder climates we have shorting growing seasons. Many plants wouldn’t have enough time to grow, flower and fruit if we waited to plant seeds until the frosts ended. Another reason to start seeds early and inside is to keep the seedlings away from all the super hungry spring animals. By the time we plant the seedlings outside they’ll be big enough to withstand a little munching from a slug (probably not from a bunny or deer though!).
"Sow # weeks before last frost":
“Last frost” is the average last frost in your area based on historical data. There is a 30% chance there could still be a frost after that date, and there is a very good chance your last frost could be weeks before this date. In Connecticut our last frost is somewhere between the last week of April and the last week of May. The date depends on many factors including, elevation, latitude, cardinal directions, shelter from structures, nearby water, and probably more. Find your “last frost date” HERE >>> Some plants are perfectly happy to have a few frost kisses and can be transplanted a few weeks before this date. Any “tender” plants should be transplanted outdoors after this date. Also, I want to encourage you to try to follow their advice and don’t start things too early just because you’re excited. Plants don’t like to sit in pots that are too tiny, so if you start them too early you might find you have to pot them up twice. Yikes.
Days to Maturity:
This is probably the #1 most confused term. Here’s the deal: in plants that are most commonly direct seeded, the days to maturity is the time between germination and first available harvest. In plants that are most commonly started indoors and transplanted, the days to maturity is the time between transplanting and first available harvest. Weird, right? But now you know.
Seed depth:
The general rule is seeds are planted at twice the depth of their size. If the seed is 1/8″ wide, add about 1/4″ of soil on top. Some seeds are very tiny and the packet says they “need light to germinate.” In this case, you’ll sprinkle your seeds on the surface of the seed-starting mix and gently press them in so they have good contact with the soil. It is important to moisten your soil mix before you start planting so that when you water your flat, the seeds don’t sink lower than you want them to be. If you are planting tiny seeds you may want to place the whole flat in a tray of water for an hour or two so you don’t have to water from above. Cover your seed flat with a clear plastic cover like a bag or loosely with cling-wrap so that they stay moist.
Temperature for germination:
Most seeds will be happy to germinate at around 70-75 degrees (F) and will be perfectly happy on a window sill (as long as the window isn’t too drafty). There are a few exceptions, which will probably be explicit on a seed packet. Cooler germinators include many cool weather crops like spinach, broccoli, carrots, onions, and peas. Some of these plants will actually stall germination in temperatures over 65-70 degrees (F). Warm germinators need a higher temperature to germinate and benefit from a heat mat or a super warm environment. Peppers, especially chili peppers, need about 80 degrees (F) to germinate well. If you don’t have a heat mat (and you don’t need one; I don’t have one…) try putting your planted seed flat on a high shelf or on top of your fridge where the ambient air is warmer. Don’t forget about it up there though!
Days to germination:
Each seed has a general range of time it takes in ideal conditions to germinate. The seed must come out of dormancy, the seed coat must soften and crack and the sprout and first root emerge from the seed. The seed contains the first bit of nutrition that the seedling will use to do this early growing. In the radish example above, the range given is 4-11 days. This range assumes that the soil and moisture is amenable, the temperature is appropriate and the seed depth is right. If the seed hasn’t sprouted in 11 days, I would still give it another week or so before giving up. Some seeds, like carrots and parsnips, take 2-4 weeks to germinate. Don’t give up and don’t forget to keep them moist. It’ll be worth it! The moon’s cycles have a lot to do with when a seed will germinate. We find seeds tend to sprout sooner if we plant during the waxing phases (between New moon –> Full moon).
Harden off:
If a seedling goes straight from a sheltered, warm environment to an outdoor garden, it may be shocked and stunted. We go through a process of “hardening off” to ease the transition. Begin by bringing your seedlings outdoors for a few hours of daylight each day. Gradually give your seedlings more and more exposure to the natural elements for a period of about 2 weeks.
Spacing and Thinning Plants:
When sowing seeds directly in the garden or in an open seeding flat (as opposed to cells), we generally plant more seeds than we plan to keep. Depending on plant and root size, each plant needs a certain amount of space in order to live its best life. After the seed has sprouted and has grown its first true leaves, it is time to thin the plants. The best way to do this when the seedlings are in a garden is by PINCHING them, NOT PULLING. Go down to the soil surface and using your fingernail, just pinch the stem to break it off. Pulling the plant out will inevitably pull at the fragile roots of the neighboring plant, the one you want to keep.
And now, what seed packets don't say...
Seed-starting mix
Soil Mixes and Media
Used especially for starting small seeds. This type of media is very fine and light, with low fertility. It basically just creates a structure for roots to grow and an ability to hold the right amount of moisture.
Here's a simple recipe and the one I use:
Coconut Coir
2
Perlite
1
Worm Castings
3/4
Use these numbers as proportions of a mix. So if you want about 4 gallons soil, use 8 quarts of coir, 4 quarts of perlite, and 3 quarts of castings. Check out more details of this recipe here.
Add water to this mixture and use your hands to squish it all together. Make sure there are no clumps. Add water until when you squeeze a handful, the soil just holds together but no water drips out, like a wrung-out sponge. After I plant a flat of seeds I sometimes add a light layer of vermiculite to the surface. The vermiculite aids in moisture retention, prevents splash-back when watering, and reduces the likelihood of fungal infections like “damping off” and other pests like fruit flies.
Coconut Coir vs. Peat
Peat has been used for a long time in seed starting and potting mixes because it is fabulous at holding moisture and creating great soft structure for young plants. It is, however, a highly endangered resource and the harvesting of peat is destroying bog ecosystems all over the world. Luckily, coconut coir acts in the same way and is highly renewable as a byproduct of coconut processing. So even if the mix is labeled “Organic” check the ingredients. If it contains peat, please consider finding a different product or making your own using the above recipe.
Moisture, Water, Drainage
When we plant teeny tiny seeds we usually water them “from below” at first. Set the flat in a tray of room temperature water just until the top feels moist to the touch. I usually cover these flats with clear plastic and keep them moist by misting the soil surface. Larger seeds (beets, corn, squash, etc.) can be watered overhead by a gentle watering can of room temperature water.
Cold water will slow the germination of warm season plants like tomatoes, peppers, beans, or squashes. You can just fill your watering can or misting bottle and let it come to temperature for an hour or so.
Your seeding flats, cells or other media should never collect water. If it looks like water is pooling, your seeds will likely rot before they sprout and the roots will not get the aeration they need. In this case, add more perlite to your mix and make sure your flat is draining from holes in the bottom.
You may have heard various opinions about using certain types of water. Don’t overly worry about your water unless you know your tap water is extremely hard or soft. In general soft water can be more detrimental than hard water. Don’t freak out though and buy a reverse osmosis system. Just collect some rainwater and give your plants a rain drink once a week or so. They’ll be fine.
Containers:
Some plants (tomatoes, cabbages, sunflowers, borage) grow deep roots quickly and should be grown in deeper soil. Other plants have more spreading roots and thus don’t need as much depth and can be grown in less soil (lettuce).
Some plants have very tender roots and don’t like being transplanted. These plants do best in biodegradable pots such as CowPots, newspaper or soil blocks. Beans and peas are examples of fragile rooted plants. Other plants have highly resilient roots and can be planted in an open flat and pricked out and transplanted when they have their first leaves. Tomatoes are well known for having very rugged root systems.
Light:
Depending on the brightness of your bulbs, you’ll want the height of your lights to be about 3″- 8″ away from the tops of your plants. If your seedlings are long, leggy and floppy, it means they aren’t getting enough light. It is important to give plants lots of light as soon as you see green poke out of the surface of the soil.
