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Colorado Seed Starting 101: Advice From Rick’s Grow Team




If you want lots of fruits and veggies come summer, the best gardening advice we can offer you is to start early and indoors. Colorado’s growing season is too short for many garden favorites.  Eggplants, peppers and tomatoes do not have enough time exclusively outdoors to produce a bountiful harvest. That being said, we’d like to share some of our own techniques for extending the season. Starting seeds inside is the best way to get this jumpstart on the season. And I can thank our spectacular Grow Team, particularly Emma & Jenn, for the helpful advice! If you are a seasoned gardener, or this is your first season growing a garden, enjoy some of our best tips for being successful at seed starting.

Days To Maturity & Pre-Planting

As previously mentioned, Colorado’s growing season is short. When I visited Missouri one time, I was amazed that communities had tomatoes ready to harvest by June, and all of them were grown outside, from seed! Colorado gardeners can have full bushels of tomatoes come June also; we just have to start early and indoors. The best way to plan for this is to research days to maturity for each plant and start according to these specifications. Depending on when the plants reach maturity, you should sow seeds indoors an additional 4 to 6 weeks before the last frost date. For example, peppers need about 85 days to reach maturity. With a bit of math, 85 days turns into 12 weeks. Maturity refers to the number of days it takes the plant to produce fruit. Add four to six weeks on top of that for germination, then research your area’s last frost date through a trusted weather channel. Colorado Springs is typically on May 8th or even Mothers Day. Just to be safe, we’ll use Mother’s Day as a guide for our planning going forward. Subtracting roughly 14 weeks from May 10th means the optimal planting date is January 18th. A little late, but that doesn’t mean you can’t plant peppers; they’ll just fruit a little later! You can find maturity information on the back of seed packets. We’ll also provide a link below this paragraph to one of our favorite references, Colorado State Extension, and their incredible Colorado Vegetable Guide. Click here to read!

Drainage, Drainage, Drainage!

A major seed killer is overwatering, which is easy to do. However, raw seeds need to remain moist until cracking appears, which creates a conundrum in terms of watering. Both Jenn and Emma recommend a combination of fine-draining growing medium and special watering techniques to avoid this. In terms of growing medium, our Grow Team actually starts seeds in vermiculite. It has to be coarse for the best aeration, but if you water less, fine-grade is alright. Seedlings will stay in vermiculite for two weeks, then will be transplanted into a special seed soil or Foxfarm’s Happy Frog soil. Why do we not keep seeds in vermiculite permanently until they can go into larger pots? Vermiculite isn’t great at storing nutrients for seedlings, which obviously isn’t a benefit if you want to grow delicious, healthy, and strong vegetable plants (or any plant). And in terms of watering, we use misters, not watering cans or a hose. Keep the medium moist but not soggy. It’s the Goldilock’s ideal for the seeds!

Warm Bottoms, Cool Tops

A trick to creating a perfect environment for seeds, Emma told me, is to keep the following phrase in mind: warm bottom, cool tops.  She and her grow team raise a majority of our vegetable starts in one of our many greenhouses, including a major crop of our tomato varieties. In the greenhouse, we have enough space to use heating mats, and regulate temperature with a greenhouse heater. We also understand many readers aren’t as lucky when it comes to such growing conditions. If you live in an apartment, a small home, or are on a budget, where do you even start, much less keep in mind the mantra “warm bottoms, cool tops?” Let’s translate the quote and make alterations. Seeds should have a warm and inviting substrate to thrive in, preferably one heated by a heating mat. Hence, the “warm bottoms” of the first half of the mantra. Whether growing in a greenhouse or at home, we always recommend a heating mat. It emulates summer growing temperatures that vegetables, like peppers, need. We carry various heat mats, some with timers and others without, that would work perfectly for a smaller grow setting. These mats should be set between 80 to 70 degrees Fahrenheit.

What about the meaning of “cool top?” In our greenhouse, there’s the heater, but even now, the environment is still considered “cool” compared to summer temperatures. The contrast between soil and air tells the seed which direction to grow, establish roots in the warm earth, whilst the stalk should reach to the cool air above ground. The air cannot be too frigid, however (hence the greenhouse heater), or else the sprout will have stunted growth or die. In a home operation, we recommend growing seeds in a warm spot with full sun, using a plastic greenhouse cover only when the sun moves away to keep in the heat. The space you plan to grow seeds in, shouldn’t go below 68 degrees Fahrenheit.

Light On The Subject

This is essential for growing seeds at home, Jenn mentions, “as much light as possible is essential for starting seeds.” And we’re not talking about keeping seeds by windows. We’re talking grow lights, which sounds like overkill to many, but if you want to avoid leggy plants they’re a must. Have you ever grown seeds at home and noticed that as they mature, they become long, stringy, and weak? This is what we mean by leggy. These plants are desperate for light, but without enough, they cease to function since photosynthesis depends on sunlight. Jenn recommends keeping the grow light as close as possible, and eventually “upgrading” seed domes (which is where the grow light can rest upon). This is the best way to avoid leggy seedlings.

Quick but helpful tips (we hope) to Colorado seed starting! We know gardening can be expensive, and some of these supplies will be, but in the end, nothing beats the pride of using your own plant starts for the summer. Plus, your wallet will thank you in the long run, too! Happy gardening!