Q: How do you feel about spreading used coffee grounds around my flowers? I have read that they make good fertilizer, but I also have read that they are acid. Should I be careful which kinds of flowers get coffee grounds or how thickly I spread them?
A: Coffee grounds are great for flower beds, and for vegetable gardens also. It is true that they provide a little fertilizer, but they are most important because they are organic. That means that coffee grounds serve the dual purpose of holding water and creating air spaces in the soil. All soil particles which are not derived from crushed rock lead to healthy roots and thus to healthy plants.
It is true that coffee grounds are slightly acid. It is also true that changing the acidity or alkalinity of soil is close to impossible. Spread coffee grounds as thickly as you like; only if you buried your flowers a foot deep would a problem ensue. In gardening, as in many things, moderation is a good principle to follow.
Q: For several years I have tried to grow cauliflower, but I succeeded in getting heads only once. In the other years the plants just bolted to flowers. My cabbage grows just fine. Why isn't the cauliflower doing equally well?
A: Although cauliflower is related to cabbage, it is much more sensitive to temperatures. Cauliflower likes weather that is neither too hot nor too cold. Cold nights when the plants are young cause them to "button up," to make button-sized heads which produce so few edible flower buds that they are not worth eating.
Avoid the damaging cold nights of early spring by planting cauliflower at midseason — later than cabbage and earlier than tomatoes. I plant cauliflower two weeks later than cabbage. There may still be nights cold enough that the cauliflower plants need to be covered, but with a little care they will not be shocked into a production failure. Be especially watchful and prepared to cover them when the plants have six leaves. That is when they are most sensitive. Waiting too long to avoid the cold is not a solution, because cauliflower does not like heat, either. It will form premature small heads if the weather turns hot before they have had time to develop fully.
Cauliflower varieties may be more or less sensitive to temperature, and trial and error is sometimes the only way to learn which varieties grow best in a particular garden. Early varieties are more likely to be successful than later ones. No matter the variety, though, consistent soil moisture is critical. Dry soil also causes cauliflower to bolt to flowering.
Q: I want to plant fruit trees this year. How can I choose the best trees? What tricks are there for planting them?
A: The trees most suited to the local climate will be for sale at local nurseries. Some nurseries grow their own trees; if not, they will have purchased them from local growers. A tree which began life in a milder climate will find it hard to adjust to Montana weather. One that always has lived here will grow quickly when transplanted to its permanent home.
Look for a small tree, not a large one. Within two years its size will have surpassed a bigger tree, which would be more stressed by moving. Choose one of perfect shape; that will not change.
Plant the tree as soon after purchase as possible. If it is a bareroot tree, soak the roots in a bucket of water while digging the hole, but not more than 24 hours. Dig the hole only as deep as the roots but wide enough that they are not cramped. Plant the tree no deeper than it was at the nursery. Even if the tree is in a container, fill the planting hole with the dirt that came out of it. Do not add any rich soil, compost, or manure, and do not fertilize the tree for at least a year. Spread an inch of mulch around its trunk.
Do give the tree enough water. Water it every day for the first week and every other day for the second one. That is the best success trick of all.
Master gardener Molly Hackett, whose motto is “Never trust a gardener with clean fingernails,” welcomes your questions. Send them to 1384 Meridian Road, Victor, MT 59875; call 961-4614; or email firstname.lastname@example.org. Please include a garden-related subject line in emails. Hackett writes a twice-monthly Dirty Fingernails opinion piece for the Missoulian.