This week’s winter-ish weather aside, the anticipation of warmer and longer days ahead has Coloradans eager for spring temperatures and outdoor projects. If you’re somewhat of an impatient gardener, we have some good news. According to CSU’s Master Gardeners – You can start your spring garden prep in Colorado, even before the threat of snow has officially passed.
Here are a few tips to get you started:
Ideally, you should begin winter watering in late fall as our moisture drops off. But, plants can still benefit now if there is no natural moisture. Surprisingly, Colorado’s snow doesn’t have a lot of moisture content during the early winter months. Therefore, it’s important to water shrubs, trees, and other plants at least once a month on a warmer day when the ground is not frozen.
Unsure if your soil is frozen? You can push a screwdriver into the ground to test.
Prepare Your Soil:
Now through April is a great time to add compost and work it into your soil. This gives those nutrients time to mellow a bit before planting. If you mulched with leaves around trees and bushes, wait until late spring to clean up the leftover debris. The mulch helps insulate and retain moisture. If you mulched your vegetable garden, disease-free organic material can now be mixed into your soil to add new nutrients for this year’s planting.
The general recommendation for a raised-bed mix is to combine four inches of existing soil, three inches of topsoil, and two inches of an amendment, like compost. You can also opt to purchase topsoil and amendment already combined.
A word of caution: Be careful not to over-amend. If you’ve added amendments for several years in a row, additional organic matter this season may not be necessary.
Finalize your infrastructure
Now is an excellent time to build raised garden beds or relocate, repair, or expand existing beds. If planning for vegetables, note that most vegetables need at least eight hours of sunlight. The morning sun is generally not as intense as afternoon rays. Make sure the beds won’t be shaded by neighboring structures or trees, and avoid low spots where your drainage isn’t good. Consider putting beds in a high-visibility location near a water source to make things easier on yourself. If your beds are where you can see them daily, you’re less likely to forget to water.
You can use rocks, stones, concrete blocks, lumber, or bricks to construct sturdy and aesthetically pleasing raised planters. Railroad ties are not recommended due to the potential compounds in the treated wood leaching out of them. However, cedar and other natural rot-resistant woods are perfectly okay choices.
If you are constructing new beds, remember to add a decomposing barrier underneath. Newspaper works well and can help prevent grasses or weeds from coming up.
Getting ready for flowers
Although the general rule here in Colorado for outdoor gardening is not to put anything outside until after Mother’s Day, between now and then is an excellent time to replace the soil in your gardens and pots.
If you just can’t wait, potted columbines and pansies handle cool seasons much like annuals. Ornamental kale also does fine in Colorado’s cooler springtime temperatures.
You can prune shrubs in March and April, but be sure to finish pruning your trees before the end of March.
Remember not to prune more than 25% of a tree or shrub. Don’t prune early bloomers, like lilacs or forsythias, or you’re likely to lose the blooms. Do those in summer after they have finished flowering.
In March, you can cut down ornamental grasses but wait until April to prune rose bushes.
We hope you find this guide to Spring garden prep in Colorado handy. We only have a few weeks to go before the winter weather leaves for good, so make the most of your growing season with these easy-to-tackle garden tasks!