Mulch is a good gardening habit but not mandatory. But, ooh boy, do the benefits make it worth the effort! A really good job of mulching your garden usually
- Inhibits weed germination and growth (and not only are weeds unsightly, but they also they steal resources from your plants!)
- Holds in soil moisture, protecting your plants from drying out so fast
- Moderates soil-temperature fluctuations (this benefit is especially valuable during that turbulent-weather period in spring when you don’t want your plants to be stressed)
- In cold-winter areas, protects plant roots from winter cold and helps prevent frost-heaving, in which plants are literally pushed out of the ground by the natural expansion and contraction of the soil as it cools off and heats up
- In hot-summer areas, helps keep plant roots cooler
- Depending on what you use, adds a bit of welcome nutrition to your garden as it breaks down Sound like good enough reasons to use mulch? Yeah, I thought I’d convince you.
Of course you can adjust your soil’s pH! Gardeners do it all the time when they know their lot in life is extreme soil, or even when they’re just trying to please some special fussy plant. It’s not a big deal. You just dig in something that nudges the pH in the direction you want it to go:
- If your soil is too acidic: To raise the pH, dig in dolomitic limestone, bonemeal, or wood ashes. How much? I knew you were going to ask that! The answer has to do with how much ground you want to alter or improve. If you really need to adjust the pH, I strongly recommend you get that lab-analyzed soil test, because the lab can give you good, tailored directions on what to do and how much amendment(s) to add. Just so you know, though, the general rule of thumb for adding granulated limestone is between 5 and 10 pounds per 100 square feet of garden area.
- If your soil is too alkaline: To lower the pH, dig in some acidic organic matter such as peat moss, sawdust, well-chopped leaves from oak trees, or pine needles. Alternatively, you can add calcium sulfate, iron sulfate, aluminum sulfate, or powdered sulfur. If you don’t let the sawdust, leaves, or pine needles decompose somewhat before adding them to the soil, they can leach nitrogen from the soil as they break down. And too much peat moss can waterlog the soil as well as make it quite acidic. Consider adding no more than one part of organic amendment to three parts soil. You need professional advice on application rates if you decide to go with powdered sulfur or other additives.
You can do a little detective work by observing which native plants are thriving and then confirming that they have a preference one way or another. Or you can run a soil test — use either an inexpensive kit or arrange one of those more-intense tests where you take soil samples from various parts of your yard and mail the dirt in to a lab. The nice thing about doing this more intense test is that the lab report not only tells you the pH (and a few other useful things, like the nutrient levels in your soil) but also gives you specific recommendations on how to improve or alter your soil. Check with your local Cooperative Extension Service — workers there may be able to run the tests for you at a minimal cost.
The pH (and you can find various arguments about exactly what pH stands for) is the measure of your soil’s acidity, and it’s often a huge area of debate among gardeners. I try to keep this discussion simple so I don’t make your head spin, especially if you have little or no acquaintance with chemistry. Too low of a soil pH means the soil’s too acidic, and too high of a pH means the soil is alkaline. Generally speaking, you want your soil pH to be on the slightly acidic side for the vast majority of garden plants. Extremes are rarely good.
The pH scale ranges from acidic to alkaline — 0 to 14, with 7.0 as neutral. The really good news is that many soils are fairly close to neutral. Acidic or alkaline soil isn’t bad soil or bad for plant growth per se. But the minerals in the soil that are important to plant growth and health have a tough time getting to the plants when the pH isn’t right for the particular plant. Scientists have discovered that beneficial soil bacteria don’t function well unless the soil pH is relatively close to neutral. These bacteria are important because they break down organic matter and make sure nutrients are in forms that plants can use.
Of course, some plants prefer or are well-adapted to pH levels that are a little more acidic or a little more alkaline. And some soils are naturally so; when in doubt, you can take your cue from the native plants. Examples of plants that like acidic soil include blueberries, azaleas, rhododendrons, most other broadleaf evergreens, and heather. So in the New England states, where many soils are acidic, you see native blueberry plants. And if gardeners in that region want to grow blueberry bushes (albeit improved, bigger-sized fruit varieties), they should have good luck.
Examples of plants that like alkaline soil include penstemon, dianthus, baby’s breath, and beets. So in the Southwest, where many soils are more alkaline, you see native penstemons. And if gardeners in that region want to grow these flowers (native species or improved selections), they should have good luck.
Yeah, I also talk about compost in the fertilizer section, but compost is useful and necessary to your garden in so many ways other than as plain fertilizer. Because it’s organically rich, with good texture, compost is just about the best thing you can add to soil. What works best really depends on the type and fertility of your native soil, but you can’t go wrong digging in quite a lot of compost. Compost lightens heavy clay soil and gives needed substance to sandy soil. Less-extreme soils can still benefit.
In any event, half-compost and half-native soil isn’t excessive. Some really keen vegetable gardeners forgo native soil altogether and use 100 percent compost to grow incredible crops. Using solely compost is most feasible in raised beds. Roots relish it. You can get healthier, happier plants. Don’t use soggy or overly dry compost. Compost should be fully decayed, dark in color and crumbly in texture. This issue is more significant with homemade compost than the bagged, store-bought sort. For homemade, you’re fine if you take it from the bottom of the pile (most store-bought composters have a convenient hatch there).
Whether you’re planting a new rose, a young perennial, a handful of bulbs, or a bunch of annuals, always dig a hole both deeper and wider than the root ball. This practice gives you an opportunity to make a great new home for the plant, an area the roots can eagerly expand into. Either scoop some compost into the bottom of the hole (where a lot of root growth should occur) or mix compost with the native soil (try a 50-50 mix).
Skip this step of mixing in organic matter for trees and shrubs. The latest studies show that trees and most shrubs do better in the long run if you keep the plants in native soil; in amended soil, they may not grow past the planting hole. However, if you plant them in native soil, they can easily grow beyond the planting hole. In general, potted plants like a lighter medium. Go ahead and put a handful or two of compost in along with the potting soil, but don’t be heavy-handed.
Quite a few gardeners make their own compost, a process that can take three months to a year to complete. Many gardeners also use a compost bin for this process, though you can just pile the compost in an isolated and sectioned-off portion of your yard. Your compost pile should be kept slightly damp but not soggy. Stirring or turning the material every few weeks can speed up the decomposition process. When the compost is dark brown, is cool to the touch, and has a pleasant “earthy” smell, it’s ready to use.
Good material choices for mixing and making your own compost include
- Chopped-up leaves (smaller pieces decompose more quickly)
- Any young weeds that have not gone to seed
- Old lettuce or other salad greens
- Prunings from healthy plants
Don’t compost weeds that have gone to seed, any diseased plants, or any plants that have been sprayed with herbicides. Also, animal fats or spoiled meat are not recommended and often attract rodents.
Whether you’re using store-bought or natural fertilizer, such as compost or manure, most plants like to be fertilized at planting time, just to get off to a good start. Thereafter, you may fertilize again on a monthly basis. Reduce or stop when fall’s cooler weather arrives. Fertilizer inspires fresh new growth, and you don’t want that then — fall is a time for plants to slow down and approach dormancy, and cold weather can damage new growth. (You should, however, feed the lawn in autumn to stimulate root growth; feeding grass in the spring pushes excess leaf growth that the roots can’t support ).
If you’re using store-bought or chemical fertilizer, read the label to figure out how to deliver the fertilizer and how much to use. Some fertilizers work best if you dig them right into the soil; others are better delivered in dilute form when you water. The label can also tell you how much to use per square foot of garden area and how often to apply. For bagged organic fertilizer, read the label; otherwise, do some research on your own.
More is not better! (Though if you’re fertilizing with compost, using too much is almost impossible — see the next section.) Plant fertilizer is like aspirin. The right amount is beneficial; too much is harmful. So don’t get carried away. Remember that some fertilizers are types of salt, and high concentrations of any salt can kill plants. Always read the label and follow the directions carefully. To get the amounts right, you may have to pull out the tape measure and figure out how many square feet of lawn or garden you need to cover. Some gardeners like to fertilize their plants half as much, twice as often. That’s perfectly okay. Just make sure you dilute properly and get your measurements right. (Gardeners often use this technique with roses and many houseplants.)
If you have a large flower bed or big vegetable garden, one fairly easy and undeniably efficient way to give it a dose of organic matter is to plant a cover crop at season’s end: You grow plants just to maintain and improve the land during the off-season to prepare the garden for next year. Sow the cover crop according to the directions on the bag and let the plants grow. It should hog the area to sufficiently thwart weeds. And of course, a cover crop provides plentiful organic matter and limits erosion. Good choices include annual rye, buckwheat, clover, winter barley, and winter rye. Here are some tips based on your region:
- In mild-climate areas: Sow the cover crop in mid-fall. When the plants are about a foot high and are still soft and green, dig them in (if practical) or till with a rear-mounted rotary tiller. Then let the plants decompose or meld for a month or more.
- In cold-climate areas: Just plant the cover crop in fall and let winter kill it. The stuff will decompose at least somewhat, with or without snow cover. Till the area in spring, when the ground is workable again. Wait a few weeks before planting the area.
