Question: I work at a school as an environmental teacher and we have strips of what used to be lawn near each classroom. The lawn was not properly taken care of, and now it is just a variety of weeds that the school gardeners mow every week.
I got the idea to put in native plants and mulch with bark and to use it in a lesson plan with the kids. We could compare water usage before and after the project. My question is: What would be the best way to plant in these areas? Should I disturb the soil as little as possible or till it and then plant? I realize some of it has to do with the kind of soil, which seems to be clay loam. Right now it's receiving too much water from the sprinkler system. Thank you for any suggestions you may have.
Answer: I commend you for your goal. The ecology of native plantings offers many teaching opportunities for students. If you are going strictly native, you don't have to till. You will probably need to weed intensively both before planting and during establishment, especially if you're starting with seeds.
In cold regions, dig dahlia tubers when frost blackens the foliage, and store them in a frost-free place until spring.
If you can't reroute the sprinkler system, your selections may be limited a bit, but you can still grow a variety of species to represent several local habitats. Oak woodland, juniper scrub, chaparral, and wetland plant communities each have their own distinct ecological lessons. Focus on low-maintenance plants that offer food for pollinators, flowers, fruit, or other tangible products. Allow kids to help plan and start the gardens with potted plants, cuttings, and seeds. Have fun.
Question: Recently, I was wandering through a large garden center and discovered rubber mulch. Can it be used like regular mulch? Is it any good?
Answer: Rubber mulch is great for playgrounds, horse arenas, and large landscapes. It is a recycled material marketed to last a "lifetime." For trees and shrubs in a large landscape, rubber mulch is fine. But use organic mulches (wood chips, compost, etc.) for annuals, perennials, edibles, and mixed gardens. Although they are not long lasting like rubber mulch and must be replaced annually, organic mulches supply nutrients and improve soil tilth as they decompose.
Question: I have numerous dahlia plants that are just now finishing blooming and acquiring dark and dead foliage at the base of the plants. Should they be completely clipped back now or should I wait until the entire plant has died back?
Answer: Always remove dead foliage and flowers. If the whole plant looks bad, feel free to cut it down completely. However, if you have healthy foliage, let it continue to grow and feed the tuberous roots.
For those in temperate climates, wait until the entire plant has died back — typically after the first frost. Dig the tuberous roots and dry them in a frost–free area. Place them in sand or soilless mix. Store in a cool, dark, dry location.
For more info on storing summer bulbs, read the final paragraphs of Moving Houseplants Back Indoors.
Question: Will cutting down a 25-year-old box elder tree make the box elder bugs stop multiplying in our yard? There are millions that we are whacking daily with a flyswatter. Do they need a box elder tree to survive?
Answer: Now is the time when box elder bugs seek the warmth of indoors. Fortunately, they don't bite and aren't a threat to ornamental plants or even box elder trees. The bugs are more of a nuisance than a pest. However, that does not help when you are swatting all the time.
Box elder bugs also feed on maples and ashes, but they typically only lay eggs on female, seed-bearing box elder trees. If yours is the only mature box elder in the area, removing it should reduce their numbers. Good luck.
Question: I live in South Carolina and have a fig tree I bought nearly 10 years ago that hasn't grown more than 2 feet tall. We planted it in full sun in good soil, and we give it lots of compost. Every year it seems to almost die in winter and then comes back with lots of leaves in spring and looks happy through November. But it won't grow any taller. My mother-in-law also lives in South Carolina and has had a fig tree in her yard for 15 years. It's now taller than her two-story house! What am I doing wrong?
Answer: This is a classic conundrum: "Why can't I grow the plant that my friend, who lives right down the street, grows beautifully?" There are two likely answers: your mother-in-law has a different variety of fig or she has a warmer microclimate. You can buy a hardier variety or, better yet, root a cutting from your mother-in-law's tree. If it still won't grow, then your microclimate may be too cold for figs.