When Should I Plant In Colorado
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Did you know the average Colorado growing season is only 157 days?
The question of when to plant is a critical one. Colorado provides a unique spring weather experience. Colorado’s high altitude and unpredictable weather make it an exciting place to garden. Colorado is no stranger to powerful early spring snowstorms and then beautiful, sunny 60-degree days in the same week.
It is easy to be tempted by the sunny days and warm temperatures in March and April, but the biggest challenge is dealing with frosty evening and early morning temperatures.
PRO TIP: Find your last frost date. Frost date is the average date of the last freeze in spring and the first fall frost. A little research can help make an informed decision about your planting schedule. We trust The Old Farmer’s Almanac for this data.
Planting In The Ground
When planting in the ground, it is recommended that gardener’s hold off until the last frost, which typically occurs in late April to mid-May in Colorado. Most annuals are safe to plant after the last frost occurs in the spring and will bloom continuously until the first frost in the fall.
However, hardy flowers can be planted as soon as the soil in your garden can be worked, even before the last frost. Hardy plants include annuals such as Dianthus, Diascia, Flowering Kale, Lobelia, Osteospermum, Phlox, Vinca Vine, and perennials such as Columbine, Digitalis, Hosta, Lavender, Mexican Feather Grass, Poppy, Rudbeckia and Shasta Daisy.
Half-hardy flowers can be planted a few weeks before the final frost. Half-hardy annuals include Angelonia, Bacopa, Calibrachoa, Cosmos, Dichondra, Gazania, Gerbera, Ornamental Grasses, Petunia, Verbena and perennials such as Bee Balm, Delphinium, Cone Flower, Roses, and Perennial Salvia.
Tender flowers should be planted when there is no change of frost for the rest of the season. Tender annuals include African Daisy, Alternanthera, Asparagus Fern, Begonia, Bidens, Caladium, Canna, Celosia, Cuphea, Dahlia, Guara, Impatiens, Lantana, Marigold, Nemesia, Portulaca, Scaevola, Sweet Potato Vine, Thunbergia and Zinnia.
Hardening Off
"Hardening off" is gardener speak for acclimating a plant. It helps the plant adjust from the growing conditions in the greenhouse where it was grown to its new home outside.
This acclimating period allows the plants to ease into their new home instead of being thrown in without time to adapt.
Hardening off plants increases successful transplanting and takes a few days to complete the process.
After bringing your plant (that’s been growing inside a greenhouse) home, give it five to six days to get used to the change in environment. First, set the plant in the shade for a day or two. At night, bring it into the garage. Repeat this process the next day. Over the next few days, gradually introduce more sun, and stop taking it in the garage at night.
After five or six days, your plant will have had a change to adapt to its new environment and have a better change of successfully growing through the season.
Planting In A Container
Are you anxious to start planting some annuals for early color? When the days are warm, but the nights are still too cold to keep tender plants outside, planting into containers that can easily be moved indoors or inside the garage at night could be an option for you.
We have deemed this juggling act as the “garage shuffle”. During the day when the weather is warm and the sun is shining, you can keep your planted containers sitting outside. Bring your plants indoors at night when the temperatures drop. If it drops below freezing, it is recommended that you bring them inside the house and not keep them in the garage where the temperature is likely still too cold for your plant friends.
InColor begins shipping plants into retail stores at the end of March and early April because: Who can resist the gardening urge when that hint of spring starts peeking through?
Planting Vegetables
Like flowers, vegetables have different hardiness levels and thrive in difference conditions.
Cold-hardy vegetables can be grown in early spring conditions. Cold-hardy vegetables include spinach, onions, asparagus, chives, fennel, garlic, peas, potato, radishes, strawberry, broccoli, cabbage, cauliflower, lettuce and rhubarb to name a few.
Warm-weather vegetables should be planted when freezing temperatures have completely passed. Warm-weather vegetables include squash, tomatoes, peppers, eggplant, basil, cucumber, cilantro, dill, rosemary, sweet potatoes.
PRO TIP: Get a customized planting calendar for your zip code.
PRO TIP: If you are planting herbs and vegetables from seeds, you can start them indoors and transplant into your garden at the appropriate time. Just remember to harden them off for a better chance of success.
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