by Blaine Howerton | NorthFortyNews.com
A season-by-season planting guide to help Northern Colorado gardeners grow stronger, longer-lasting harvests.
Knowing when to plant can make the difference between a thriving garden and a frustrating season of slow growth. In Northern Colorado, where late frosts and temperature swings are common, planting at the right time isn’t just helpful—it’s essential.
Spring often tempts gardeners to get seeds in the ground early, but patience pays off. Cool-season crops are the first to go in, while warm-season vegetables need to wait until the soil and nighttime temperatures catch up.
By mid to late April, gardeners across the Front Range can begin direct sowing hardy crops like peas, lettuce, arugula, and root vegetables, including carrots, radishes, beets, and parsnips. This is also the time to transplant onions, leeks, and early brassicas such as broccoli, cabbage, and kale.
These crops are built for cooler conditions and can handle light frost. In fact, many will perform better when planted early, before the heat of summer sets in.
As May begins, you can wrap up those early plantings and continue adding greens in succession. Staggering plantings every couple of weeks—especially with lettuce and other quick growers—helps create a steady harvest instead of a single overwhelming one.
But the real turning point comes later in May. Once nighttime temperatures consistently stay above 50 degrees—often around the last week of the month—it’s time to shift into warm-season planting. This is when tomatoes, peppers, and eggplant can finally be transplanted outdoors. At the same time, you can direct sow crops like beans, corn, cucumbers, squash, zucchini, melons, and even potatoes.
It’s tempting to rush these heat-loving plants into the ground early, especially during a warm stretch. But planting too soon can stunt growth, setting plants back more than the early start helps. Cool soil slows root development, and cold nights can stress or damage young plants.
June becomes your cleanup window—an opportunity to get anything missed in the ground and begin thinking ahead. Late in the month, gardeners can start fall crops like broccoli and cabbage indoors, preparing for a second growing season as temperatures cool.
By midsummer, the focus shifts again. July and early August are ideal for sowing another round of root crops and preparing for fall harvests. And as September arrives, cool-weather favorites like lettuce, arugula, and radishes return for a final round before frost.
Even October has its role. Planting garlic and sowing spinach before winter sets in allows these crops to establish and come back strong in early spring.
The rhythm of a Northern Colorado garden isn’t about a single planting day—it’s about understanding the flow of the season. Cool crops first, warm crops later, and a second wave as summer fades.
Get the timing right, and your garden won’t just grow—it will produce steadily from spring through fall.
Make North Forty News part of your morning. Get Northern Colorado’s top stories, weather, and events every day at 5 a.m. in our Daily Update.