23.3.11


Spring Flowers- Part 1-  Periwinkle ( Vinca)



Every year in Miami, Spring sneaks up on us. The official date is on the calendar, but we are caught by surprise every March or April. I hear the same comments about the heat every year. I hear myself saying the same thing: " it's getting hot really fast", and "wow, that afternoon sun is really intense". This increasingly intense sun also leads to some drought problems, and we seem equally surprised that we have to water our Impatiens or Pentas more often. The Impatiens in particular are looking tired, beginning to get thin, and need more fertilizer than just a month ago. Many other annuals wilt every afternoon, since the sun if getting higher in the sky, and the early Summer rain is still a month away or more. The "mean season" of late March through the first week of May results in bleached plants, sunburned gardeners, and frazzled nerves. What can we do to relieve these problems, and are there really better plants to use as annuals ? There are many answers, and they can help make your garden a much easier place to work in. 


"wild" type Periwinkle

Consider that in most parts of the country, water is getting scarcer. Although there may be some very rainy periods and even flooding, the overall availability of ground water is getting worse and worse. We should look at water saving techniques in every venue of gardening, as well as every other venue in our daily lives. Let's look at one variety of annual that likes drier soil conditions than, say, and Impatiens, the gold standard of annuals. In many parts of South Florida, we see the wild Madagascar Periwinkle, a cheery little plant that pops up in dry parking lots, rock piles, and unexpectedly on rooftops. One would think that someone would harvest the seed from it, grow it, and make a lot of money by selling a totally drought tolerant plant, but the plant is rather fussy to grow commercially; it hates being potted, and is none too fond of being watered as are many annuals in commercial production.

There are numerous hybrid versions of it, one of which is the Cora Series of Vinca ( Periwinkle), produced by Goldsmith Seeds, this series has great resistance to the disease which has plagued Vinca growers for decades. It has excellent growing properties in a very sunny area, not so good in heavy shade. In containers on a balcony, in ground beds in parking lots, and garden center edges, this plant keeps cranking out flowers through the hottest weather, and seems indifferent to our heavy Summer rains. Of course, if you live in a dry climate the old garden types can grow well for you, and I envy the people of the semi-arid climates since they can grow many things we cannot. ( They probably envy us our ability to grow the moisture loving plants). 





The old methods of annual-bed preparation still hold true: deep soil cultivation, addition of bone meal and slow-release fertilizer, good drainage, and sufficient water to keep plants healthy. Please notice I did not specify a schedule for watering. I think far too many people believe that plants grow on a fixed schedule, no matter the weather ! This is not only a waste of water, but a prescription for failure. I am not suggesting you watch your plants all day long, but a careful eye toward the weather helps a lot in keeping plants healthy. In the case of Vinca, raised beds of very well-drained medium are required. Enough water to establish the plants before the rainy season followed by irrigation-on-demand watering during the rainy season is all that is needed. The reward is a long term show of flowers, sometimes 6 months or more. Choosing a different type of plant to meet your needs is easier than changing all the conditions to meet the plant's needs, unless you have a prerequisite for having a certain kind of flower in your yard.Some gated communities actually specify what type and color of flower needs to be planted in your yard, and when to plant. These communities need to better understand the diminishing groundwater situations, and the more realistic sensibilities of xeriphytic or low-water landscaping options. Water is a resource we cannot live without, and the water wars of 150 years ago will come again, sooner than we think. Periwinkle is another tool we can use to bring color to our gardens, save us some gardening effort, and save a great deal of water in the process. 

Craig Morell
Pinecrest Gardens 




   

"wild" Vinca- Periwinkle




































           

4 comments:

  1. I use this plant alot...its def in my top 5 plants for south florida! My only complaint: self-seeds (so alotta babies2abort!)....small price2pay!

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  2. Great article. Very informative! I have these planted around the base of my palm trees here in Cutler Bay, FL and they look great!- Alex

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  3. I moved to Florida almost a year ago. There were dark pink vinca's already growing in the front of the house and they are still going strong. I never watered nor fertilized them. It may be the rainy season, but we are in drought here in Hobe Sound. From what the neighbors have said, I think these flowers have been in place for years...certainly beyond the 6 months of expected lifetime.

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  4. I moved to Florida almost a year ago. There were dark pink vinca's already growing in the front of the house and they are still going strong. I never watered nor fertilized them. It may be the rainy season, but we are in drought here in Hobe Sound. From what the neighbors have said, I think these flowers have been in place for years...certainly beyond the 6 months of expected lifetime.

    ReplyDelete