Grateful Growers ~ Wholesale Premium Bedding Plants

CARING FOR VINCA IN CENTRAL TEXAS
OR HOW TO NOT END UP WITH DEAD GARBAGE IN YOUR BEDS

Casey G., Sales Mgr. / Assistant Grower
Grateful Growers Inc.

Vinca, sometimes called Periwinkle (or that plant that turns black and dies) by the retail crowd or people with wives, is one of the most love/hate crops I've dealt with in my years in the commercial horticulture industry. People love them for their colors, deer resistance, pest resistance and relative disease resistance, but likewise hate them because of the few diseases that they are succeptible to. More often than not, both landscapers and their clients will shy away from Vinca in spite of all their strengths simply because of the glaring weakness they have to both Pythium and Phytophthora root diseases. Sadly for those missing out, these two killers can (in most cases) be avoided without any chemicals or other more harsh (and usually expensive) methods.

First and foremost comes irrigation. 90% of all the cases I've seen where people lose whole beds of Vinca are due to overwatering. Vinca are Summer plants, and as such they thrive in dry, arid climates. While all plants need to be well-watered in the first weeks following tranplant, Vinca rarely need to be watered more than twice a week in Texas Summers, sometimes three times weekly in especially dry years. Because Pythium and Phytophthora both thrive in moist soil, beds which are constantly wet are perfect breeding grounds for the diseases. Both need to be in soil that is constantly wet, and cannot survive in dry medium. In most cases, simply reducing the frequency of irrigation can turn Vinca from your Summer headache into a Summer favorite.
Keep in mind the first rule of bedding plant irrigation: You can never water too much in one sitting. This doesn't just apply to Vinca. Don't be shy about watering for 30 minutes or more with overhead sprinklers or drip-hose watering. Saturate the soil well, and your plants will develop stronger, deeper, more healthy root systems; and you'll spend less time and money on water (especially if your bed is in an area under water restrictions).
This brings us to the next most important thing to remember: Never water unless the plants are dry. If you eat a meal even when you aren't hungry, it can have a negative impact on your health. The same is true of bedding plants. Some plants dry out fast and need to be watered four days a week. If you watered a cactus four days a week, what would happen? Keep this rule in mind when selecting your bedding combinations. Try to select things that will follow a similar watering schedule. Imagine the incompatibility between Alyssum and Vinca, for example.

Which species you choose is also important. For those who have little or no control over their irrigation, choosing a different series of Vinca can sometimes help solve the problem. The Cora series in particular is a newer variety of Vinca that has all of the same benefits as the more standard Pacifica and Cooler series, but with the added strength of a much higher resistance to Aerial phytophthora that has become prevalent in this area in recent years. Simply by selecting plants with different genetics you can tailor your beds to survive in under conditions that might kill other species of the same plant. Again, irrigation control can solve most of these problems, but selecting a stronger seed can be a cost-effective (or cost-par) way to avoid beds full of dead material.

If all else fails, use a broad spectrum, systemic fungicide. The best example of this is a chemical called Subdue and its derivatives. Though Subdue and similar chemicals can stop the spread of Pythium and Phytophthora, it cannot heal existing damage. It can help prevent the disease for as long as it persists in the soil, but it will not keep your beds disease-free all season long. Moreover, most end-users will not be able or willing to spend the kind of money these chemicals cost. Retail versions may exist, but are in much more diluted form and are usually not as effective. Chemical treatment can even involve EPA guidelines and restrictions in certain cases, and so should only be used as a last resort. Make sure that you have tried everything else and consulted with experts before going forward with chemicals, as there are usually (as this article can atest) safer and cheaper ways to achieve results.

Some plants are not the best choice for Central Texas. Some folks want Plumeria tress, but have no way to care for them in the Winter. Some want to plant Crepe Muertles in the July or think that Impatiens look best in the Summer sun. People are always going to want what looks good; a picture of a Day Lily looks good all year. Many growers of bedding plants tend to assume that Vinca are bad plants simply because they've had a bad experience with them. After all, spending $200 on that fancy new lotion seemed like a good idea until you had to go to the hospital because of an allergic reaction that almost killed you. Fortunately, Vinca can perform beyond well in the Texas Summer as long as you're willing to care for them in the way that nature intended. You can't grow that Plumeria in Winter because it will turn black and die in the frost, and you can't drop Vinca into a mud-puddle and expect them to survive any better. As always, knowing your plants before installing them will do wonders to help you get the most out of your money, and we here at Grateful Growers can help fill you in if you aren't sure or want it explained in a way that is less like a horticulture textbook.

Here's hoping your next experience with Vinca is a (non-verbally) colorful one!