Low Humidity

Question:  In the winter, with the furnace being used, the air in our home tends to be very dry.  What problems might this cause for my violets?  How can I increase the humidity?

Answer:  This can be a problem for many of us.  Though they don’t need very humid, damp, conditions to thrive, violets won’t be happy when the air is very dry.  At relative humidity levels below 30% or so, they, and you, can become uncomfortable.  Symptoms can include premature bud loss, or smaller than usual blooms, or brownish edges to blooms and foliage.  We’ve also notice that leaves on many varieties will tend to “spoon” (edges cupping upwards) under very dry conditions.  Keeping plants properly watered can be a problem too, since so much moisture is quickly evaporated from the leaf and soil surfaces.

If one grows enough plants, lack of humidity is rarely a problem.  Since water evaporates from the soil and the plants themselves, grouping enough of them together increases the humidity for all of them.  If this isn’t possible, or isn’t enough, another solution is to place the plants on a damp surface which will evaporate water and increase humidity.  This might mean placing plants on a wet tray of gravel.  The gravel serving to keep the pots above the water level.  Watering plants with capillary mats also provides additional humidity as water is evaporated from the wet blankets.  Using a community tray to wick water a number of plants does the same.  Of course, if you’re just as uncomfortable as your violets, using a humidifier, or installing one on your furnace, might be the best idea.

Blossom Not as Described

Question:  Several months ago I ordered several plants.  One of the violets was supposed to be ‘Cherries ‘n Cream’.  As I’ve grown this plant, it has bloomed well and is very healthy, but the blooms are single to semidouble reddish stars with “no edge at all”.  The foliage is as described.  What can this particular plant be, if it’s not ‘Cherries ‘n Cream’?

Answer:  This is a question received by one of our mail-order customers, since we guarantee all plants to be true to description.  Since the plant was true in every way except for the absence of the white edge on its bloom, we guessed that cultural conditions, the summer heat in particular, might be to blame.  Many edged varieties, particularly those with blossoms thinly edged white, tend to lose this edge when grown in very warm conditions.

It seems that her growing conditions, particularly the heat were, indeed, the problem.  This is the reply we received from her. “I’m relieved to know that it is just a matter of growing conditions.  What you said makes sense because I have been growing this plant in my kitchen (much warmer) with natural lighting versus in my basement (much cooler) under florescent lights.  ‘Cherries ‘n Cream’ doesn’t seem to appreciate a lot of direct light like some of the other violets.  I’ve also noticed that my variegated varieties have turned more green with the warmer weather.  I wonder if this affects all bicolor blooms as well?”

All of these symptoms are consistent with growing in a very warm environment.  Much, sometimes all, of the of the variegation can be lost in foliage, and many multicolor blooms can turn solid.  Fortunately, the variegation on most varieties will return with the cooler weather.  Unfortunately, this may not be the case with those having multicolor blooms, such as “fantasy” (i.e. spotted or splashed) and edged blooms, that have turned a single, solid, color.

Fertilizer and Variegation

Question:  I purchased ‘Rob’s Whippoorwill’, which originally had variegation on the outermost ring of leaves, but it has now started to turn all green.  I feed all of my violets with ‘Miracle-Gro African Violet Food’ (7-7-7 formula), every time I water, 10 drops per quart.  Am I feeding too heavily for a variegate?  Do they require more or less light than the average violet?  This is my first try with variegates, and I’m not happy with the results.  Am I doing something wrong?

Answer:  Not necessarily.  To begin with, ‘Rob’s Whippoorwill’ is a Champion (or crown) variegated variety that can easily lose its variegation with age.  In this case, it’s probably the variety, not you, that’s the source of your frustration.  In explaining further, we’re about to say a few things that will fly in the face of conventional wisdom.

Beyond the habits of the variety itself, our personal experience tells us that the single, most important, factor in determining the amount of variegation is temperature.  Variegation is always greater when plants are grown in a cooler environment.  Variegates can be sensitive to overfeeding, especially since heavily variegated varieties seem more likely to show signs of fertilizer burn on leaf margins and tips.  It’s also true that, because of the lesser amount of chlorophyll in their leaves, they grow slower and process relatively less food than do all-green varieties.  Still, feeding them significantly less, or feeding them low-nitrogen fertilizers, won’t necessarily produce heavier variegation–it just means that the green portions of the foliage will be a lighter shade of green.  We feed our variegates the same balanced fertilizer as all of our other violets, since our goal is a plant whose leaves have green portions that are dark green, and whose variegated portions are bright white (or yellow, beige, etc.).  Conventional wisdom also says that variegates require less light.  We suppose, in theory, that they do.  But in practice, we’ve grown them precisely the same as all of our other violets with no noticeable difference.

If you really want to grow heavily variegated varieties, simply grow them in as cool an environment as possible.  By cool, we mean night temperatures as low as 60-65f degrees, and day temperatures less than 70-75f degrees.  For those varieties whose foliage tends to turn green with age even when grown in moderate temperatures, here’s a trick we use for growing showplants.  Remove all but the center row or two of foliage, and remove all but a third of the root system.  By “starting over” these all-green variegates, the new growth (assuming, again, that your conditions aren’t too warm) should be variegated, at least long enough to show.  For those not growing for show, is it really that important?  After all, are the blooms on an all-green “variegated” plant any less pretty than those on a non-variegated variety?

Tight Centers and Hairy Leaves

Question:  Several of my violets have tight centers and hairy leaves.  I may have overfertilized when I switched fertilizers.  But when I read my magazine, the description of tight centers and hairy leaves seems to come up when describing cyclamen mites.  How do I tell the difference?  I do have misshapen blossoms on some plants, but thought maybe condensation was taking place.

Answer:  It’s hard to know for sure, since so many things can cause these symptoms.  A cyclamen mite infestation is the easiest conclusion to jump to but, fortunately, it’s often the wrong one.  If it is only a fertilizer problem, try leaching the plant by running clear water through the soil, then watering without fertilizer for a short period.  The tight center growth should begin to loosen.  Another possibility is environmental.  Both very warm or very cold temperatures can cause tight centers, though “hairiness” of the leaves makes cold temperatures more likely here.  Are these plants near a drafty window or in a cold corner of the basement?  Too much light can cause tight centers, too.

Cyclamen mites are very tiny insects, visible only under magnification, being less than 1/100th of an inch long.  They can be eradicated with minimal plant damage, if the infestation is caught in an early stage.  On the occasions that we’ve had to deal with this pest, we’ve had to use chemicals to eliminate them (yes, we do use chemicals, but only when absolutely necessary).  We’ve had good success with Avid, which seems to be the miticide of choice among larger commercial growers.  Unfortunately, it is costly ($70 or more for 8 oz.) and comes in quantities that most small growers won’t be able to use.  Given its cost, we wouldn’t advise the small, hobby, grower to expose themselves to toxins for the sake of a few violets.

In any event, we’d suggest that you separate your problem plants from your healthy ones.  Investigate one possibility at at time.  If the problem is bad (i.e. more like mites), root some healthy leaves and throw out the plants.  Wash the leaves in a mild soap (like Ivory) and room-temperature water before rooting, and segregate the resulting plantlets until you are sure that they, too, haven’t inherited the problem.  If you must use a chemical, follow all instructions and take every precaution for safety.  Since their life cycle is about 14 days, repeated treatments will be necessary to eradicate them–say, at least 3 applications at weekly intervals.

1 3 4 5 6 7 35