The growing season in Grand County is short but there are ways to extend the season and eke out extra growing time by protecting your plants from frost. One way is to provide a physical barrier to protect your plants. A greenhouse is a great way to do this but can be cost prohibitive if you are buying a prefabricated kit. There are lots of free plans on the internet if you want to build one yourself using old windows, plastic sheeting or panels. Keep in mind proper ventilation because with our intense sun, the temperature inside a greenhouse can exceed 100° in a matter of minutes! A cold frame is essentially a mini greenhouse box built on the ground a few feet high with a clear covering on the top for accessibility.
Another idea is to place covers called cloches over individual plants. Traditional cloches are glass but can be fashioned out of repurposed plastics like milk jugs or two liter bottles with the bottom cut off. Entire gardens, containers or individual plants can be covered with white frost cloth fabric which can provide several degrees of warmth with some ventilation. Clear plastic sheets can help warm soils and presprout weed seeds in the spring but they don’t allow your soil dry out so I like to use a black landscape fabric that is marketed for weed control because it allows air flow to the soil.
Microclimates are areas in the landscape that have something to absorb the sun’s heat during the day and release it at night. This is a low tech, easy way to keep your plants warmer utilizing solar thermal gain. Microclimates are typically found on south west facing aspects that have a structure like a building, the back of a raised bed or rocks. You can also take advantage of thermal gain by filling containers with water, the darker colored the better and placing them in the garden. There are products on the market that go around the plant and have compartments that can be filled with water.
One way to get a jump start on the growing season is to buy transplants for plants such as broccoli, cabbage, lettuce, kale, and various herbs from local sources in late spring when it’s close to the last frost date. The other option if you are like me and yearning to start gardening is to start plants indoors. First thing is to get your timing right on when to start your transplants. For most vegetables this is 4-8 weeks before planting outside, generally April to early May.
There’s a wealth of resources about starting seeds yourself on the web but here are the basics. Seeds can be started in any clean container that has drainage and is filled with a quality potting soil. The depth to plant the seed will be listed on the package. I will usually plant 3–5 seeds per container and thin to the strongest seedling with small scissors. As the seedlings sprout, the soil will need to stay evenly moist by covering them with some clear plastic and checking them often. Most essential to starting seeds indoors is lots of light. They can be grown in a sunny window and rotate them often to keep the seedlings from becoming leggy (really tall with long spaces in between leaf branches). I use fluorescent or LED grow lights a few inches above the top of the seedlings and brush them with my hand a few times a day to prevent the seedlings from getting stretched out. When it is close to time to plant the indoor seedlings into the garden, they will need to be hardened off. This is gradually adapting the tender seeds to harsher outside conditions by taking then outside in a windproof, shaded area for a bit each day eventually having them be used to being out in the full sun without stress.
Be sure to check out https://extension.colostate.edu, the Colorado Extension Service’s website has much of the information we’ve shared with you plus so much more!