Wittwer Vegetable Primer Available

Q. I received the Wittwer vegetable “bible” but I must admit, I'm a little confused by the title, as It seems to be pertaining to Moapa and Virgin Valleys and not the Las Vegas Valley.  As longtime residents of the Las Vegas Valley, don't those valleys have a different climate than the Las Vegas Valley?

Dr. Sylvan Wittwer's vegetable garden in Logandale, Nevada, eastern Clark County in southern Nevada. Vegetable growing conditions are similar to Las Vegas.

A. Yes, they do. It is slightly different, a bit warmer to be exact. The climates between the two valleys are very similar. Both valleys are in the Eastern Mojave Desert. It’s hard to find information from a source like Dr. Sylvan Wittwer for the Las Vegas Valley.

Dr. Sylvan Wittwer was the past extension vegetable specialist for Michigan State University but originally from Hurricane, in southern Utah in Washington County.

            Dr. Wittwer was the retired Vegetable Specialist from Michigan State University when he moved to our eastern Mojave Desert climate. He grew vegetables in this climate for eight years before he moved back to Utah. It’s difficult to find reliable information in the Las Vegas Valley from such a notable source.

If you want, contact me at xtremehorticulture@gmail.com and I will email you the entire pdf copy.

Vegetable Growing in Moapa and Virgin Valley Southern Nevada

 Requests for Dr. Witwer’s information on raised bed gardening, his “Bible” I call it, overwhelmed and surprised me. I just finished sending out copies to everyone and my fingers are tired! (Ask me to send it to you ((morrisr@unr.edu)) because UNR doesn't carry it anymore.) 

Dr. Wittwer was the former vegetable extension specialist for Michigan State University before he retired to southern Nevada. In Logandale, Nevada, he maintained a large in-ground vegetable garden for many years before moving and eventually passing away. Logandale, in its agricultural area called the Moapa Valley and located about 60 miles north of Las Vegas, is slightly warmer but has a similar climate to Las Vegas.

Use His Recommended Varieties First

It is essential to use his recommended varieties but his recommendations on fertilizers and pesticides can be substituted for “organic” forms if you prefer. When using raised beds, or Bartholomew’s “square foot gardening”, look for more compact forms of the same variety to learn from. Vegetable breeders “earn their pay” by recognizing popular varieties in regions would be even more popular with homeowners provided they have enough space to grow them. They concentrate on making them small or changing their fruiting habits in some way. The ‘Early Girl’ variety of tomato is now available from Burpees as an example as a “bush” or determinate type instead of the continuously vining type called “indeterminate”.

Reasons for Raised Beds (or Modified Raised Beds Called "Containers")

There are many reasons for constructing raised beds; rocky soil beneath it, uninhabitable because of pests like nematodes, small space requirements, beautification, etc. A type of “raised bed” are nursery containers. 

Even smaller “raised beds” such as ornamental containers in the landscape can add beauty and height to traditional gardens. Unlike larger raised beds they can be easily emptied, scrubbed clean, sanitized, and refilled again with new soil. Remember to fill them to within one inch of the container “lip” to maximize their soil depth and ease their heat dissipation. Use the same or similar soil mix in the container to make watering them easier.

Remember pots get hot on the outside unless the pot has something shading it. Double potting them (so they have an air space) is one answer in keeping the heat under control.

UNCE Orchard Weather Report for March 2014

No significant weather events occurred during March except some temperatures below 45F which could account for some chilling injury to sensitive plants. See the report below.

Do Liners at the Bottom of Raised Beds Help or Hinder?

Q. I'm setting up some raised beds for planting this spring and wondered about water evaporation from the soil. Since water retention in the soils here in Vegas is an issue due to the heat would it make sense to put a liner in the beds to help keep the moisture from draining out so quickly?

What to Use on Vegetable Seedlings Decimated by Insects

Q. The day after I planted seedlings in my 4x8 raised bed I noticed they were decimated by some kind of insect. When I was amending the soil I noticed some small worm-like critters in the soil. I sprayed Bt but it evidently didn't do anything to help the situation. I was told to use a powder called "milky spore disease" to kill any grubs or grub-like insects in the soil. Have you ever heard of this product? They said it works and I only have to apply it one time. Can you advise me on this product and where I might find it or some other solution? 

Decimated pepper

 

A. The milky spore product only works on Japanese beetle and a few closely related insects which we do not have in southern Nevada. It is a bacterium and works rather slowly, if it will work at all, on pests we have in southern Nevada.

            Bt works differently. It works on those insects that mature or pupate into either moths or butterflies. So if the immature insect turns into a beetle for instance it will not work. So without knowing which insect is doing damage it is hard to know what will work.

Cutworm larva

 

            The other alternative is to use a conventional pesticide approved for use on vegetables and has insect grubs or larvae on the label. These insecticides leave a poisonous residue for longer-lasting insect control.

            This time of year Bt is a good product to use because it will control many of the insects causing damage right now. Look for products with a label that says Dipel or Thuricide. Forget the milky spore bacterium control in your case.

            I am sending you a picture of what the cutworm larva looks like and its adult form, a moth. I will also post it on my blog. Bt can be sprayed on the soil and left undisturbed (no hoeing or irrigating after the application) for a few days but you have to repeat your applications to get any long term control.

Corn earworm moth adult
http://ipm.illinois.edu/ifvn/volume15/frveg1506.html

            This is the time of year that moths are flying, mating, laying eggs and larvae are out looking for food. Usual cutworm damage is at the soil surface, not on the leaves.