MARCH
2008

 

 

 

By
B. Rosie Lerner
 
Purdue
Extension
Consumer Horticulturist

 

 

 

 

 

3-6-08

Question and Answer

Q. My aunt of 99 years passed away and left me 12 African violets. I've tried taking care of them like she did, but I can't get them to bloom. Could you please give me some tips?

A. African violets are generally quite easy to care for, adapting quite well to typical home conditions. The most critical factors are proper light, growing media, nutrition and moisture. They will bloom best with long days (14-16 hours) of bright light (~10,000 lux = 900 foot candles). If natural light is not adequate, you can use artificial lighting to supplement. But they also require a dark period (8 hours) daily to initiate flowers.

The growing media should be a well-drained, high-organic-matter mix. Many garden centers sell media blended specifically for African violets, but any good quality potting mix will do fine. Similarly, there are many brands of fertilizer that offer an African violet formulation, but they will do fine on just about any blooming houseplant-type product. Be sure to follow the label directions in regard to application rates. There are many types of formulations available, including those that provide very dilute product with each watering, to a bit stronger once a month, to slow-release formulations, etc. Use whatever is most convenient for you.

Many gardeners tend to "kill them with kindness" by watering too often. African violets perform best when allowed to dry slightly between waterings. It is true that they do not tolerate cold water; it causes unsightly spotting of the leaves. Many violet fanciers prefer to routinely water from the bottom, allowing water to be absorbed from a saucer up into the pot. To avoid excessive build-up of mineral salt deposits, water thoroughly from the top every fourth watering or so, and discard the drained water. Allow the water to reach room temperature before applying, to avoid the leaf spots.

More information on growing African violets can be found in Purdue Extension bulletin HO-10, http://www.hort.purdue.edu/ext/HO-10.pdf.

Q. We have some wild black raspberries down over the hill from our house, but their production has not been worth the chiggers, or the walk back up a steep hill. I have no idea how old these plants are. Is there anything I can do to increase the odds of a good crop from these bushes for some wonderful raspberry pies or to eat with homemade ice cream? 

A. Oh, now you've got my mouth watering just thinking about summer berries! Wild raspberries aren't likely to be quite as productive as modern hybrids that are raised in a garden environment, where they can be tended to on a regular schedule. But you could give them a boost by doing a little bit of pruning and clearing away weeds to allow better light exposure. Raspberries have biennial canes, meaning they grow foliage only the first year, overwinter as dormant canes, flower and fruit the second year, and then die back to the ground. Black raspberries also spread considerably in a number of ways, including seedlings from dropped berries, root suckers and cane tips layering down to the soil. So, wild plants often are tremendously overcrowded and, perhaps, also overrun by weeds. Regular pruning by completely removing canes after fruiting and cutting back the first-year canes about halfway back will keep the plants a bit more controlled. Thinning out overcrowded, spindly plants will also help. This won't keep the chiggers from biting!

Q. At our new 40-acre property, there are black raspberries dividing the woods and the tillable field. They produce nice berries. Are there any special techniques to tend to them? I know that Mother Nature does a very good job. Can these be tended to similar to blueberries? One area can be cut down, as the deer know where to pass through to enter the woods, and there are no livestock on the property. Could these be transplanted to another area? Is pruning a good way to boost the fruit crop? Thanks for your time and assistance.

A. Black raspberries grow quite differently than blueberries, and their care requirements are quite distinct. In addition to annual pruning, weeding and thinning, some fertilizing would be helpful to keep the plant productive. About 3-5 pounds of 12-12-12 or similar analysis fertilizer for each 100 feet of row should be sufficient. Apply as a band about 3-4 inches from both sides of the plants in the early spring, before growth begins.

And, in times of drought, watering to ensure that the plants receive about 1 inch of water per week will help plants optimize yields. While irrigation is important, any time Mother Nature doesn't provide enough, it is especially critical from the time the plants bloom through harvest. Also, keep in mind that the summer-cropping raspberries initiate flower buds in later summer, which is when droughts are typical in Indiana.

If the plants are productive and healthy, you could try to transplant existing plants to another area. Or, you could try tip layering the plants to create young plantlets that would be easier to move. But wild raspberries are frequently afflicted with virus and propagating from those plants will bring the virus with them. If you want to establish a new planting, it might be best to purchase virus-free plants from your local garden center.

For more information on caring for black and other types of raspberries, see Purdue Extension Bulletin HO-44 http://www.hort.purdue.edu/ext/HO-44.pdf.

 

Writer: B. Rosie Lerner
Editor: Olivia Maddox,