If you have gardening questions, Paul James has the answers.
Question: What is the difference between the terms conifer and evergreen? Are they interchangeable?
Answer: Evergreen plants retain their leaves year-round, as opposed to deciduous plants, which lose their leaves and go dormant during the fall and winter months. There are broadleaf evergreens, such as acubas (pictured), magnolias, laurels, hollies and azaleas, and there are needle-leaf evergreens such as pines, junipers, spruces and yews.
Conifers are plants that produce cones, most of which have a familiar cone look and shape, although on junipers, the cones look more like berries. But here's an important point: not all evergreens are conifers, and not all conifers are evergreen.
Most of the broadleaf evergreens don’t produce cones. But larches, bald cypress and ginkgos are deciduous plants that do produce cones. And to make things even more confusing, there are plants that behave as evergreens in the south but are deciduous in the north, such as Abelia. There are also so-called semi-evergreens, which, depending on the severity of the winter, may be either evergreen or deciduous, such as certain Viburnum.
Question: Do slow-release granular fertilizers really last up to six months or more?
Answer: It depends. This popular fertilizer is a synthetic formulation that’s encapsulated in a material that slowly dissolves to release the nutrients.
The rate at which the little beads dissolve is dependent on the temperature of the soil. The manufacturer’s claim is based on soil temperatures of 70 degrees Fahrenheit. But in container plants in particular, soil temperatures can easily reach the mid-80s, even higher. And higher temperatures greatly reduce the time during which the fertilizer remains effective.
Question: Have you seen an elderberry named Black Lace?
Answer: You bet! It’s Sambucus nigra 'Eva'. Black Lace, a European elder, has been getting a lot of publicity lately, and it’s no wonder. This USDA Zone 4 beauty has a striking purplish-black foliage, and the leaves are deeply cut.
Black Lace can tolerate full sun in the north, but it needs afternoon shade in the south. It will quickly reach a height of six to eight feet by roughly six feet wide, although it can be pruned back to a more manageable size. And it produces creamy pink flowers in the spring.
Question: Can you grow blueberries in containers?
Answer: Absolutely! The variety known as 'Sunshine Blue' does particularly well in containers. It’s a highbush blueberry called Vaccinium corymbosum.
Most blueberries require highly acidic soil, betweeen 4.5 to 5.5. But this one can tolerate a much higher pH, in the neighborhood of 6.5, which is close to the pH of most potting mixes. It’s also self-pollinating and requires only 150 chilling hours to set fruit, which means it can grown much farther south than other highbush blueberry varieties.
Question: Do polymer water-absorbing crystals really work?
Answer: They sure do. When added to potting mix for container plants, they absorb several times their weight in water, then slowly release it, so moisture levels remain fairly steady.
And now there’s a gel form that you inject into the soil with a caulking gun, so if you forget to add the crystals at planting time, you can still add them later.