Good mulch brings good bugs

Leaves under butternut squash and tomatoes

A gentleman of my acquaintance asked me what to do about squash bugs.  I said that I never really have a problem with squash bugs.  Turns out that the people he is helping with their farm are using plastic mulch to control weeds and row covers to try to control insect pests. 

I pointed out that what controls bad bugs are good bugs, predators that eat the plant eaters, and the most effective ones require good mulch like leaves to live under.  When you have plastic mulch or bare soil, you lose all the spiders, centipedes, ground beetles, and soldier beetles, to name a few of the most effective predators in the garden.

Warming rocks under peppers.  They warm the soil at night, cool it during the day.

Almost all of these predators live exclusively under loose mulch and rocks.  Soldier beetles spend the spring month of their adult lives flying, eating aphids, mating, and laying their eggs under mulch, where their larvae live under the mulch the remaining 11 months of the year, eating anything they can catch and kill.  If you have no loose organic mulch, you will have no soldier beetles laying eggs, and few or none of the others.

He said that the plastic mulch is needed to keep weeds down.  I said that leaves do that.  Not only do they keep sun off the seeds that need light to sprout, but they are a poor sprouting surface, as they dry out quickly, so seeds that land on top cannot sprout either.  Only larger seeds can get through 2 inches of leaves, and they are easily pulled; it is the tiny seeds that need sunlight on soil that are hardest to control without mulch.

4x8 sand and rocks under peppers and melons.  Insects are not under sand, only under rocks.  Sand is too hot.  Walk-on fir bark is beyond.

Plastic mulch cannot feed soil, while leaves are the natural food of worms and other detritus eaters, who turn them into soil.  One eater of detritus is the earwig, which many think of as a pest.  They are rather creepy in their habit of hiding in flowers and foliage during the day and coming out when they are brought into the house, but they don’t generally eat live plants; they eat the fungus out of dead or living leaves and can actually eat fungus, like rust on hollyhocks, out of your plants. 

Wikipedia considers earwigs omnivorous and says that they eat insects and plants.  Scientists seem to have missed that they love the fungus-infected parts of leaves.  They are said to eat corn silks as well, but I always have many earwigs and no corn silk damage.  Without fungus-ridden rotting leaves to eat, earwigs have only the softer parts of live plants to eat.

Two inches of leaves is great for stopping weeds and feeding soil.  12 inches or more can make wonderful soil and grow huge plants as they decompose.  Start next year’s garden by gathering your leaves this fall, rather than giving them to the trash company for compost.  They will make wonderful compost in your garden if you just let them lie there, and add to them.

Control Cobweb Spiders with Mist

The "cellar spider," family Pholcidae, is our most common local cobweb builder and the one referred to in this article.  They grow up to an inch or so across.  Black widows and their relatives are more commonly considered cobweb spiders, going by the Internet.  

Cobweb spiders have hatched, and are dirtying houses with their dirty little webs.  Unlike other web builders, a cobweb spider doesn’t clean and repair its web; it camps until the web gets dirty and then moves on to another spot, the homeless vagrant of the web-spider world.  A dirty, visible web is useless to the spider, except to steer flies into its new, invisible web.  But they sure mess up a house, inside and out, and shrubbery as well.  Cobwebs scream neglect to thieves and encourage other disorderly conduct, like littering and breaking windows.

Last summer’s fires were very hard on cobweb spiders and other web builders, showing up their webs with ash.  Cobwebbers starved except under cover; they could not build new webs fast enough, though they sure tried, covering shrubs all over town.   There have been relatively few cobwebs this spring until now.  

Daddy Long Legs, AKA harvestmen, family Opiliones, are not spiders, having one body section, not two.

Daddy long-legs have become common where they were rare, as they don’t build webs, but just walk around.  Cobwebs certainly mess up their hunting range, and could be a hazard to them.

Rain is also hard on cobweb spiders, because they are delicate, and too much water can stick their legs together.  Rain also shows their webs, so they build webs under cover until the weather is dry, when they spread into the shrubbery.  This is another good reason to use sprinklers rather than drip or soaker hoses, besides making rain.

A customer’s neighbor in her duplex has rough siding covered with tiny, dirty spider webs, with larger webs under the eve on his front porch, but she had few on her portion of the duplex, and she has needed little web cleaning thus far this year. 

This standing mister usually sells around $10.

Last year, during the fires, she started using misters to keep her plants happy, settle the smoke and breathe easier, and she has loved the results.   When they are on, it takes only a few minutes for them to show all the webs within 8 feet, allowing this gardener to clean them off with a web duster. 

There are many brands of this tool available on the web.

A web duster, a pom-pom shaped broom head that can be attached to an extendable pole, is also needed for cobweb spider control, since as soon as the misters are turned off and the webs dry out, they are good for catching food again, and the mist doesn’t reach to the high eves.  Using a duster alone, it is an endless battle to keep the cobwebs down.  The two together can do wonders.

If you don’t have misters, cobwebs in shrubs are better controlled with hoses and spray nozzles that adjust from spray to jet than with a web duster.  Or you can use a sprinkler and web duster.  But the jet reaches inside the shrubs where you can’t see.