With spring here (at least that’s what the calendar says), the anticipation of warmer and longer days ahead has Coloradans eager for spring and summer projects.
For the impatient gardener, there is good news. You can prepare your garden in spring, even during Colorado’s cooler months.
“Today, you can continue ‘winter’ watering and start pruning and planning,” said Khursheed Mama, a 15-year Colorado State University Extension Master Gardener, of Fort Collins, Colorado.
“You can get excited about gardening and the new season,” she said. “It’s time to think about new gardens, redesigns, updates, and planning, whether for vegetables, perennials, annual flowers, trees or shrubs.”
Here are Mama’s tips for preparing your garden in spring in Colorado:
Winter watering in Colorado
You should start winter watering in late fall as our moisture drops off, but Mama said plants can still benefit now if there is no natural moisture.
Colorado snow doesn’t have a lot of moisture content during the early winter months. For that reason, it’s essential to water shrubs, trees and other plants at least once a month on a warmer day when the ground is not frozen.
“Think Thanksgiving, New Year’s, Valentine’s Day and Easter as good cues for winter watering,” Mama said.
You can push a screwdriver into the ground to test if the soil is frozen.
If you mulched with leaves around trees and bushes, wait until late spring to clean up the debris. The mulch helps insulate and retain moisture. If you mulched your vegetable garden, disease-free organic material could be mixed into your soil when you add new nutrients for this year’s planting.
Prepare your soil and garden beds
“Now and into April is a fine time to add compost and work it into your soil,” Mama said. “By doing that, it gives those nutrients time to mellow in the soil before 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, such as compost. You can sometimes purchase topsoil and amendment already combined.
“Be careful not to over-amend,” Mama said. “If you’ve added amendments for several years in a row, you may not need additional organic matter.”
Get your garden infrastructure in place
Now is an excellent time to build beds or relocate, repair or expand existing beds. If making raised beds, don’t overthink the design. You can use rocks, stones, concrete blocks, lumber or bricks. While railroad ties are not recommended due to the potential compounds leaching out of them, cedar and other natural, rot-resistant woods are fine.
If you are making new beds, add a barrier underneath that will decompose over time. Newspaper works well and will help prevent grasses or weeds from coming up.
Plan where your beds will go. Most vegetables need at least eight hours of sunlight, Mama said. The morning sun is generally not as intense as afternoon rays. Make sure the beds won’t be shaded by structures or trees, and avoid low spots for your yard where drainage isn’t good. Consider putting beds near a water source to make things easier. If your beds are where you see them daily, you’re less likely to forget about them.
Consider testing your soil
You can test your soil now to understand how to better prepare it for planting. Soil sampling in Colorado can be done through the CSU Soil, Water and Plant Testing Laboratory for a fee of $15 to $40. Try to grab soil samples about six inches down in half a dozen different places around your garden, then mix the samples together if your soil is a similar mixture throughout. Alternatively, you can test individual locations independently. It can take several weeks to get results back so plan ahead. Ask the CSU Extension office or a Colorado Master Gardener to help explain the results.
Plan your watering system for your garden
Consider the watering system you want to use such as drip or small soaker hoses. Layering mulch over the lines or around vegetable or ornamental plants can help keep soil moisture consistent and reduce water loss to evaporation until plants grow. You can also use drip systems for containers. You can plan, purchase or install these systems now, but don’t turn on the water until the risk of freezing has passed. It’s best to set a timer for your system or set it on an independent zone of your automatic sprinkler system.
Most crops don’t like overhead watering and it increases the plant’s risk of becoming diseased.
Lawn care in early spring
Early spring is an excellent time to think about aerating and fertilizing your lawn.
“Many wait until their sprinkler system is turned on to aerate, but if there is moisture in the forecast before the last frost, you can consider doing this sooner,” Mama said.
Aerating helps because lawns get compacted with use and mowing, letting weeds creep in. Aerating allows water and nutrients to penetrate your lawn promoting its health. If you rent an aerator to do this yourself, make sure you mark your sprinkler heads, so you don’t damage them.
Aerate by making lots of holes (plugs). Allow the plugs to decompose and return nutrients back into the turf system. Mowing will break up the plugs.
Fertilization is best to do before April 15.
Getting beds ready for flowers
Between now and when you plant flowers in late spring is an excellent time to replace the soil in your gardens and pots.
“I have potted columbines and pansies for Easter,” Mama said. “They handle cool seasons much like annuals. Ornamental kale also does fine.”
When to prune trees, shrubs and other plants
Mama said you can prune shrubs in March and April, but you shouldn’t prune trees past March.
“Remember not to prune more than 25% of a tree or shrub, and don’t prune early bloomers, such as lilacs or forsythias, as you’ll prune off the blooms. You’ll do those in summer after they have finished flowering,” she said.
You can cut down ornamental grasses as early as March but wait until April to prune rose bushes.
Start preparing for your garden crops
Nothing is stopping you in the winter months from gathering seeds. In fact, you may have more variety as the shelves haven’t been picked through yet, Mama said. Decide which crops you will start inside (if you plan to do that) or what you might plant from seed in the garden.
What works for planting inside vs. outside
You can start early season crops (cold- and cool-season vegetables) outside like peas, lettuce and kale. Warm-season crops like tomatoes or peppers can be started inside in late March or early April and transplanted to your vegetable garden in mid-to-late May, pending weather.
If you plan to sow your seeds directly into the ground, you must ensure that ground temperatures are warm enough to get results. Each crop requires a different soil temperature. You can check using a meat or soil thermometer. Cool-season crops can usually be put into soil in late April, but confirm ground temperatures before planting. This chart helps you determine what ground temperatures should be before planting.
Other tips from Mama when planning your vegetable garden
- Pay attention to what doesn’t like to be transplanted, for example, squash. You’ll want to put those seeds directly into the ground when soil temperatures are at least 60 degrees Fahrenheit.
- Indoor growing needs a nice, sunny window or grow lights.
- Consider the space you have and the time you’ll have for caring for your garden this summer.
- What does your calendar look like? Will there be big trips that will take you away from your garden? Water is most critical from June to August when days are hot and in the late summer when the plants are flowering and producing.
- Think about how many people you are feeding. Is there a local place where you can donate your excess produce if you have extra?
- Do you have the ability to store food? Do you feel comfortable with food preservation, such as balancing and freezing, dehydrating, canning or pressure canning? Your storage ability and comfort level with processes should be a factor in how much food you grow.
“The key is, don’t rush and start too early,” Mama said. “If you’re getting impatient and need your fix, take in the smells as you walk through your local greenhouse. I also love going to The Gardens on Spring Creek and enjoying their butterfly garden.”