Can I use an old shower curtains to solarize my yard?
Yes! Solarizing is a great way to deal with nematodes, weeds, and even get rid of turf grass. You simply cover an area with plastic, weight it down so that it doesn’t blow away, and let the heat of the sun bake the area underneath. Nematodes are parasitic round worms that live in the soil and invade the roots of plants. Once you have them, you can never truly be rid of them, but solarizing the soil does knock back the population pretty significantly. After replanting in a solarized area, the nematodes will bounce back, so solarization is really most effective in vegetable beds, where you can solarize the soil between planting seasons. To best keep the nematodes in check, you should solarize at least once a year, for at least a month (or longer if you have a really bad infestation), in early spring. Clear plastic works best here, since the sun shines through to the soil and creates even more heat under the plastic, due to the greenhouse effect. Solarizing also works well when trying to get rid of weeds and turfgrass, for example, if you’re trying to remove the grass in order to put in a planting bed or other landscape element. In this situation, it might be better to use black plastic, so that you cut the plants off from sunlight, forcing them to use all of their stored carbohydrates to grow, but leaving them no way to photosynthesize and produce food to replenish the energy that they’re using. Solarizing works very well on plants with underground storage organs like bulbs, rhizomes, and stolons that are very difficult to get rid of by pulling or even with herbicides. If you are trying to get rid of pernicious weeds, like nut sedge, or nut grass, as it’s more commonly called, or Bermudagrass, solarizing multiple times will be necessary.
Is there any harm to my yard from dumping used cat litter in the grass, but NOT using it to fertilize a garden that is used to grow food?
Well, although tossing the kitty litter into the grass a couple of times probably wouldn’t do much damage, I would advise against it, especially long-term, even in non-food areas of the yard. The small amount of cat waste in the litter is really not the issue, especially in non-edible beds, but the kitty litter itself would, in effect, become a soil amendment. Most of these products are either made from clay or silica. Clay is clumping, and does not easily break up in soil, so it would probably just stay on the soil surface as little balls. And if you have a heavy clay soil, you are already very familiar with the problems caused by having too much clay in the soil. Silica products would be less of an issue, since silica is basically coarse sand. And then there are the biodegradable products, which would, theoretically, break down over time, making them the least problematic in this situation. Unfortunately, I still think it’s best to just go ahead and send used kitty litter to the landfill.
Do you water shrubs and large rose bushes at the dripline, the same as is recommended for trees?
The answer is yes. Although shrubs and even smaller plants do not have the same root mass as larger trees, the roots still grow in a similar fashion: away from the trunk or main stem. The larger the plant, the further away from the trunk the “feeding” roots will be. These roots are newer and covered in root hairs, which are responsible for water and nutrient uptake by the plant. Older, often woody roots don’t have any root hairs, and so, don’t take up any water. With shrubs and smaller plants, the dripline won’t be anywhere near as far away from the trunk as it is with a tree, so I generally water my shrubs all around the base, and up to about half the height of the plant away. So if a shrub is 6’ tall, watering out to at least 3 to 4’ from the trunk would be sufficient. A slow, thorough soaking of the soil is much better than a quick burst of water. You’re after deeper moisture for the plant, to encourage the roots to grow nice and deep, so that it will have access to a larger soil profile. The deeper you go, the cooler the soil is, and the more protected it is from the environment, so it holds on to the water longer. In the hottest part of the summer, if we’re getting no rain, established shrubs may need water once a week, but usually not more than that, as long as you water properly.
Why wildflowers may not come up after planting outdoors
One reason may be that they were planted too deeply. An easy way to gauge how deeply to plant seeds is seed-size. The smaller the seed, the more shallow it should be planted, and corn poppy seeds are tiny. Which is why you’ll see instructions on many wildflower seed packets to only lightly scratch seeds into the soil, not plant them in holes. Another reason for sparse wildflower coverage might be an autumn rain shower, which could wash the seed away and also cover it with more soil, leading back to our first issue. I planted lots of flowers from seed in my garden when I moved to Austin. And in September of that year, I got over seven inches of rain in just one day. Needless to say, most of my seeds didn’t come up, and those that did didn’t end up where I planted them. But maybe that was nature’s way of making me relax about the perfect plan that I thought I had, and loosen up to a more natural look in my garden. The result was, of course, still quite beautiful.
This cute little mounding plant is what we in the biz would call a “sub-shrub.” With its vibrant forest green leaves and its electrified yellow flowers, damianita seems almost like a plant out of a fairy tale; maybe something that Hansel and Gretel might pass on their way to the gingerbread house. It makes a striking addition to any garden bed, but looks best planted against starkingly contrasting colors, such as pale rock mulch or decomposed granite. It is evergreen, but does require some shearing to keep it from getting too straggly in the heat. The foliage is strongly aromatic, but the plant stays so low to the ground that you may only be able to detect its scent after a rain. Damianita will only get about 12” tall, but may spread up to 2’. It loves the full sun and will not tolerate shade. It thrives in the heat and needs very little supplemental irrigation, except during the hottest, longest dry-spells. Damianita is native to areas with very poor, rocky soils, so it won’t do well in heavy clay or in areas that have been amended with organic matter. It flowers from spring all the way through fall and is listed as hardy to zero degrees, so it will also survive any uncharacteristically cold winters that we might get here in Central Texas.
Bay laurel, Laurus nobilis
This beautiful evergreen shrub is indeed the same one of culinary fame. Although I wouldn’t suggest planting one now (wait until spring), I couldn’t resist highlighting bay laurel, in honor of the wonderful privacy hedge in this week’s garden. Although native to the Mediterranean, bay laurel does very well in Central Texas landscapes. In its native habitat, bay laurel can get up to 40’ tall, but here it will remain much shorter, closer to 4 or 5’, and grow much more slowly. You can also hedge it back, to keep it manageable if it gets too tall. It also does great in a container. Since Mediterranean winters are not usually as cold as ours here, you may need to protect bay laurel on an extra cold night, especially during the first few years. But well-established trees should experience very little freeze damage, even with temperatures down into the teens, as long as those temps are not prolonged. Bay laurel prefers very rich, well-drained soil, so be sure to amend the planting area (not just the hole) with lots of compost. It requires full sun to thrive, but will struggle in areas with reflected heat and very dry air. You will need to water bay laurel regularly, but not more than once a week, once established, except in very hot, prolonged dry spells. Of course, since this is a culinary plant, you’ll want to harvest some of the leaves, which you can do at any time of the year. Since bay laurel is so shrubby, it responds well to pruning, especially if it’s healthy, and will put on new growth every time you harvest.
White boneset, Ageratina havansis
Also known as fragrant mistflower, or its more exciting name, Havana snakeroot
A shrubby plant that may get up to 6’ tall, boneset is covered in highly fragrant, fuzzy white blooms from fall through early winter. These flowers are a magnet for hummingbirds, butterflies, and other insects, since they are a rare source of late-season nectar and pollen. Boneset normally grows to about 2’ tall and wide. It’s native to rocky, limestone areas where the soil holds very little water so it prefers good drainage, but it also easily tolerates poorly drained soils, as long you don’t overwater it. It will also tolerate shady areas, but will perform better and bloom more profusely in the full, bright sun. Once blooming starts to slow down with the onset of winter, give boneset a good, heavy shearing to encourage denser new growth in the spring and more profuse blooms next fall. If you don’t shear the plant, blooming will be very sparse, since boneset only produces flowers on new wood. This plant requires very little water once established and is a great addition to any Central Texas landscape.
Red corn poppy, Papaver rhoeas, also known as Flanders poppy
As you may know, the fall is the season to plant wildflowers in Central Texas, and in many other parts of the nation. And we are blessed to have several wonderful sources for bulk wildflower seeds, making this an easy way to fill in large spaces, even on a budget. If you’re just staring out, planting wildflowers may also give you some time to figure out a more permanent plan, while still bringing beauty into the yard. The strikingly red blooms of corn poppy make a lovely combination with yellow Columbine or blue larkspur. And the leaves of poppies are very inconspicuous, leaving the most visual element, those gorgeous blooms, plenty of room to shine. The seed of corn poppies are easily saved for next season, giving you a continuous source without having to make a new purchase every year. Being true annuals, the plants will die-back and need to be removed once the flowers are all spent, and you’ll recognize when to do that when the plant stops blooming and the foliage starts to yellow and the plants dry up or fall over.