Hortiscope: Aquarium can be a planter with correct soils
Q: I was looking for information on the Web about walnut trees and found your name. I have a walnut tree in my backyard. Although I love the shade, the tree is a real pain (walnuts, squirrels, sap and broken branches). Is there any way to treat a walnut tree so that it does not bear fruit or do I just need to bite the bullet and get rid of the tree?
A: There are fruit abortion products on the market that cause the fruit to drop when it is about the size of a pinhead. That's in a perfect world where everything does what it is supposed to do. They are so hit and miss in their effectiveness that the owner usually ends up frustrated and has the offending tree removed. You might check to see if there is any local market for the wood. If it is a decent tree with a straight trunk going up 10 to15 feet before it branches out, you might get enough for the wood to offset the cost of removing the tree.
Q: I have an 85-gallon fish tank that I would like to plant cactus in. Is this feasible? The fish tank is in the basement with no natural light. There is a fish tank light on it. Would that type of lighting work or what type of lighting do I need? How deep would I need the soil to be and how far down should I plant? Are there certain types of cactus plants that would work better for this? I have potting soil for cactus/succulents or can I use sand so that it looks like the desert?
There is no drainage, so how would I address that problem? The room where the fish tank is located houses the furnace, which means it is warmer in the winter and cooler in the summer. The plan is to move the tank to a place where there is more natural light, but it's not an option at this time. Should I wait until I am able to place the tank in a place where there is more natural light? If so, would the best spot be a north, south, east or west window?
A: If you choose to grow cactus or any other houseplant in this tank, I would suggest using the potting soil mix specific for the species. In this case, the cactus/succulent mix. Since the tank has no free drainage, I would advise putting a layer of activated charcoal (about 1/2 inch thick) in the bottom to offset the accumulation of excess salts. If you want a more realistic appearance, then cover the top of the mix with just enough sand to be convincing.
It is better to have deeper soil, especially since there is no free drainage. Light is an important issue. Get and use a plant light because it would be the only source of energy available to the plants for growth. Replace the bulb after one year, even if it doesn't look any duller. Get a timer and set it for 12-plus hours of light every day. If you choose to wait until there can be enough natural light, then as much unobstructed light as possible should be sought out for the placement. Usually, it is a south or west window. During the winter months, you probably will have to supplement the natural light with a plant light to keep the plants thriving.
Q: I want to plant an old-fashioned lilac bush close to my 70-year-old oak tree. We can't seem to grow grass in the area because of the oak tree, so I'm wondering if a lilac would survive.
A: An old oak tree casts a dense shade, while a lilac needs full sunlight to grow properly and to flower. A lilac probably would grow, but not very well, especially if the shade is so dense that grass is unable to grow. Why not consider ground cover or shrubs that are tolerant to shade? Check with your local nurseries or Extension Service office to see if they have any suggestions.
To contact Ron Smith for answers to your questions, write to Ron Smith, NDSU Department of Plant Sciences, Dept. 7670, Box 6050, Fargo, ND 58108-6050 or e-mail email@example.com.