Dear Readers, (to borrow a phrase) it’s pop quiz time: What is your garden’s most important resource? Sunlight? Important, but nope, wrong answer. Plenty of water nearby? Nope again. Try one more time. Access to great plants? My Tagawa side says “yes!,” but no. The most important resource in our gardens is our soil!
Colorado is not known for having five-star soil, hence the common phrase “Colorado clay,” which is routinely followed by eye rolls and sighs of frustration. The Front Range does have pockets of sandy soil, too, but clay is much more common.
So what do we do to make our soil the best it can be? For answers, I first turned to Kelsey, Tagawa’s Garden Coach and Garden Service Coordinator.
Kelsey is one passionate gardener!
Kelsey has been in the garden industry for more than 20 years. By combining her experience, along with advice from our Garden Advisors at Dick’s Corner and recommendations found on the CSU Extension website, I’ve come up with several basic things we can all do to improve our soil and help our gardens flourish.
What if you have clay soil? Or sandy soil? Surprise! The answer is the same!
One of Colorado gardeners’ best friends is compost… organic material like leaves, grass clippings, and food scraps that have been completely broken down or “fully finished” by beneficial organisms, leaving the contents no longer recognizable as what they once were.
Compost opens up clay soil, creating tiny pockets that can hold both air and water, making it especially root friendly. The increased organic matter in the soil invites millions of beneficial microscopic organisms that break down that organic matter, eventually converting it into nutrients in a form the plants can use.
At the same time, compost can help sandy soil hold onto moisture and nutrients instead of letting these life-giving resources just drain away. For sandy soil, Kelsey recommends a few inches of a mix of 70% topsoil and 30% compost worked down several inches into the planting bed. Regardless of the type of soil, good quality compost is a great way to add nitrogen to our soil, a vital nutrient that is sorely missing in most Colorado gardens.
In both sandy and clay soils, two to three inches of compost should be added in the spring and worked down six- to eight inches, where the roots can put it to good use. A few handfuls of compost can also be mixed into each planting hole if applying it to an entire bed isn’t practical. Unfinished organic material like a few inches of dried leaves can also be added in the fall, worked into the soil, and left to decompose until spring.
Good quality compost can be made at home or purchased pre-packaged. Improving soil with compost is an ongoing process and should be the first step for any Colorado garden bed that needs help.
But how do you know how much help your garden needs?
The short answer: Get it tested. The big three so-called “major nutrients” are nitrogen, phosphorus, and potassium, or N-P-K respectively. Except for very sandy areas, most Colorado soils have adequate amounts of phosphorus and potassium. but nitrogen is a very different matter.
Nitrogen can make or break a garden’s ability to produce healthy plants. This is especially true in vegetable gardens where hungry plants quickly use up healthy amounts of nitrogen throughout a single growing season.
A soil test can help gardeners understand what type of nutrients are lacking in their soil. For a low-cost and very basic soil test, gardeners can buy a simple kit that shows them how to gather samples from their beds and test them for N-P-K.
When gardeners want a much more detailed and targeted analysis, for a modest fee CSU will test samples sent to their lab and issue not only a breakdown of the soil’s attributes, but specific recommendations on how to improve it. You can reach that site by searching for the CSU Soil Testing Lab, then scrolling down and choosing from among the varieties of soil testing they do. It’s a great way to get a baseline on new or existing beds and then track their condition every few years as you work to make your soil the best it can be.
Consistent lower-potency fertilizer is your friend
As mentioned earlier, your vegetable garden is probably the “hungriest” bed in your landscape, but perennial beds, especially those with plants that flower heavily, can use a fertilizer boost too. Kelsey’s favorite routine for perennials is to fertilize lightly but frequently. Different plants can have different fertilizer needs, but an all-purpose food will generally do the trick.
Her favorite recommendations are “Gardener’s Special” and “Happy Frog,” both of which have a strong following at Tagawa. As with any garden product, always follow the package directions and never fall for the notion that more is better. Fertilizers are salts. Using too much fertilizer can easily burn a plant’s roots, setting the plant back or killing it outright.
Fertilizer won’t improve the soil itself, but it will help support the plants in ways less-than-perfect soil can’t do by itself. And who has “perfect” soil anyway? In Colorado, achieving truly ideal soil will always be a process… an ongoing journey well worth taking.
Can mulch help the soil?
In a word, yes! Mulch is a protective layer of material spread over the soil to protect the plants, especially their roots. Mulch also helps suppress weeds and maintains more even soil moisture, which makes life easier for the beneficial microorganisms that “feed” the soil.
Mulch can be organic, formerly alive, like wood chips or herbicide-free grass clippings, or inorganic like pea gravel. The notion that mulch laid on top of the soil will rob nitrogen from the plants is a myth. As long as the mulch isn’t working down into the soil, it will only increase the bed’s fertility, not reduce it. Mulch also gives a garden a nice “finished” look. Kelsey urges gardeners to reach for the mulch anytime soil is visible.
And now for something you shouldn’t do…
If you have clay soil, no matter how much you’re feeling that late-winter urge to get out in the garden and dig, till or otherwise work your soil, as my brother used to say, “Sometimes in life, you need to sit down ’til the feeling goes away.”
Working or even walking on damp clay soil can press all of the air out of it, making it next to impossible to support healthy plant growth.
Several years ago, I made the mistake of working my beds too soon, and I paid a big price! The dirt clods I created were brick-hard, and took a good three years to break down. This garden headache is 100% preventable!
If you’re not sure, one way to test whether your garden is too wet to work is to grab a handful of soil, tighten your fist just enough to compress it into a ball, then either flick that soil ball with your finger or drop it on the ground. If it falls apart easily, you should be okay to dig, though I’d still avoid walking on it as much as possible.
Dick’s Corner is just a visit away!
If you have more specific questions about improving and caring for you soil, Tagawa’s Garden Advisors at Dick’s Corner are always ready and willing to help! It’s what they do! Just remember that our plants can be only as good as our soil, and go from there.
