Q: Is this poor plant in our office suffering from too much water? — Shanshan S.
A: The dracaena, sometimes called corn plant, has several possible conditions, and the causes might be interconnected. Overwatering, or a soil that is continually staying too moist, might be a possibility.
It’s important to realize that the brown-tipped leaves and the yellowed leaves that are most unsightly won’t revert to normal health, even if problems are corrected. We need to visualize how the plant will look with those leaves removed. Its future beauty will depend on new growth being produced to replace the damaged foliage.
Some owners of such houseplants would opt to discard the plant and begin fresh, while others would try to nurse the plant back to beauty. To do the latter, the plant should be repotted into fresh, high-quality potting mix and a pot that is about 2 inches larger in diameter. When repotting, fill the pot to within an inch or half-inch of the pot’s rim, rather than leaving a deep space, which tends to invite problems.
The old, damaged leaves will eventually need to be removed to allow new sprouts to form. It sounds drastic, but many dracaena owners have successfully rejuvenated such plants by cutting them down, leaving only a fourth of the current branch height, which usually induces new growth from the lower trunks.
The original problem of yellowing leaves and crisp edges was likely caused by an old, worn-out potting mix that might contain salt buildup and was likely staying too wet.
Q: What type of potting mix is best for repotting an amaryllis? — Twyla L.
A: A reliable method of deciding which type of potting mix to use for various plants is to learn their native habitat, and then provide a similar soil. Amaryllis are tropical natives, adapted to a soil rich in organic material.
Potting mixes that contain a high proportion of peat moss help tropical plants feel right at home. High-quality mixes, such as Miracle-Gro Potting Mix or any that are recommended by your locally owned garden centers, usually contain large percentages of peat moss, and your amaryllis will thrive in such soil.
Potting mixes that are high in peat moss are usually quite dry if used straight out of the bag. If plants are potted into the dry mix, it can be difficult to re-wet the material, as the mix tends to float around. For best results, moisten bag of potting mix, stir well and allow to remain for a day before using. The mix becomes mellow, evenly moist, and re-wetting is easy once the plants are potted.
Q: I have the vining nightshade with the red berries you wrote about a few weeks ago. It just magically appeared one year. When you said it’s toxic, is it toxic to both humans and birds? The birds feast on the berries, but if it’s killing them, I’ll take that vine out. — Lauren G.
A: The digestive system of birds is different from humans, and many berries that are toxic to humans can be eaten by birds. Birds do eat the berries of red nightshade, which accounts for the spreading of nightshade into areas it wasn't growing previously.
The term "toxic" doesn't necessarily mean deadly poisonous. The word is also used to describe harmful effects other than death. Buckthorn berries are termed toxic because they give humans severe gastrointestinal upset if eaten. Birds consume them readily, however.
Some toxic berries, such as belladonna, do cause death. In summary, there are several possible meanings when we encounter the term toxic.
You mentioned that you have nightshade, which is usually considered an invasive species. I might encourage you to remove it, as it can easily spread — not only in your own yard, but in neighboring yards as birds drop seed.
If you have a gardening or lawn care question, email Don Kinzler, NDSU Extension-Cass County, at firstname.lastname@example.org. Questions with broad appeal may be published, so please include your name, city and state for appropriate advice.