Calvin R. Finch, Ph.D., Conservation Manager, San Antonio Water System,
and Horticulturist
Week of August 19, 2002

 

Q:        Is there an annual flower I can plant now in full sun that will provide color for the autumn?  It is a hot spot.

 

A:        Three annual flowers for full sun that will perform well now come to mind: zinnias, marigolds, and vinca.  Vinca is the most drought and heat resistant.  Water it once per week but not over the top.  A layer of mulch one to two inches deep also helps.

 

Q:        The kids and I want to plant acorns from their grandmother’s tree.  How do we do it?

 

A:        Collect the acorns this autumn as quickly as you can after they fall.  It may even be best to harvest them from the tree as soon as some begin falling. 

 

Place the acorns in water and discard the floaters.  Those that sink usually have viable seeds.  Fill a one to five gallon container with potting soil and place the acorn one inch under the surface.  The plastic pots that you receive at the nursery when you buy plants work well.  The container needs a drain hole in any case.

           

            Water once per week if the soil dries to one inch and just give the acorn time.  It will probably sprout next spring if it is a live or red oak.  White oaks (bur, chinkapin, lacey) put a root down in year one and only sprout in year two.  Plant the oak in the yard when it reaches eighteen inches tall.

 

Q:        Spider mites are already on my newly planted marigolds and tomatoes.  What should I use to control them?

 

A:        Green Light Spider Mite Control uses neem oil, and some products use pyrethrins.  I think the most effective control is Kelthane.  I believe Fertilome offers a Kelthane-based spider mite control product.

 

Q:        On the Gardening Show you talked about sunflowers for summer color and bird food.  Is it too late to plant some this fall?

 

A:        No, do it now and you should beat the cold weather.  Sunflowers need full sun.  Water them in for a fast start and one watering per week if possible until the roots develop.  After four weeks they will be on their way and not require watering.

 

Q:        What is that fast-maturing tomato plant again?

 

A:        Surefire is a heat setter that produces fast enough to beat the cold weather every fall.