Weekly Express-News Article
“San Antonio Life”
By Calvin R. Finch, PhD, SAWS Water Resources Director, and Horticulturist
Saturday, March 10, 2007
“Spring Flush of Bloom for Winter
The cool weather annuals have not been very showy through January
and February because of the cold weather, but you can expect them
to begin blooming again now. Depending on the weather, snapdragons,
stocks, pansies, cyclamen and primula may bloom through May. Petunias
and dianthus have more heat tolerance and may bloom into the summer.
If it gets hot quickly the bloom period will not last as long.
To take advantage of the bloom period, the winter annuals that
you planted last fall should be fertilized and weeded. Apply slow
release or winterizer lawn fertilizer at the rate of 1 cup spread
over 50 square-feet of the bed.
Weeds are a problem for several reasons. They compete with the
flowers for nutrients and water. The foliage of weeds also compete
with the flowers for growing space and light. A pansy will not
bloom if it is covered by henbit, rescue grass, bedstraw or other
Water the winter annuals twice per week to maximize blooms. Drip
irrigation or soaker hoses are best. Hand watering works well
if you have the time. Sprinkler irrigation is a problem because
the spray is less efficient and can damage the blooms.
Control caterpillars with a BT product such as Dipel, Bio Worm
Control or Thuricide. Cucumber beetles and other chewing or sucking
insects can be controlled by Acephate or Malathion. Organic gardeners
can use the BT and try neem oil products.
A question that has to be considered by gardeners at this time
of the year if they have empty space in the garden is, “whether
it pays to buy transplants now with only a 3-4 months of bloom
Petunias and dianthus have the most heat tolerance. They would
be the best investments. Snapdragons, especially the large selections
like Rocket, are so spectacular in the spring that they are hard
to resist. Most gardeners would agree that they are worth the
cost of planting now. I put stocks in the same category as snapdragons.
They are very attractive. The most heat sensitive seem to be pansies,
cyclamen, and primula. They still might be worth the purchase
price and planting effort, especially if you can find the transplants
as sale items.
The most heat tolerant petunias seem to be VIP, Laura Bush and
Wave. They are not as ruffled or fancy as multifloras but are
tougher. My favorite petunia “Pink Wave” has very
large blooms. It and the VIP and Laura Bush will last into July
and often survive the summer to bloom again in the autumn.
To extend the bloom period of dianthus into the summer, deadhead
the blooms in late April. The easiest way to do it is to skim
them with a string-mower.
Snapdragons are attacked by 2 pests in early summer. Stem borers
take a share of the plants from now through May and then in late
May the bloom ends when rust appears in the bed. The disease moves
through the bed from the hottest section with the poorest air
movement through the entire bed. Acephate slows down the borers
and you can slow down the rust by pulling and discarding the infected
plants as they appear.
Stocks are among my favorite winter annuals. The last 2 years
they have been the best winter long performers in my cut flower
garden. The colors are attractive and the fragrance is unsurpassed
so it may be reasonable to plant stocks in the garden for 3-4
months more bloom if you find good looking plants at low prices.
If the weather cooperates pansies, cyclamen and primula can perform
well into June but some hot years they only bloom well through
April. Take good care of the ones you have in the garden now and
take advantage of low prices for attractive plants during nursery
sales as long as you realize they will not bloom all summer.
For more information on this and other gardening topics, visit
the SAWS Spring Bloom event at SAWS headquarters, 2800 Hwy 281
(Mulberry and Hwy 281) today.