Chiggers can really spoil a day in the garden

After sitting in the grass pulling weeds, I developed tiny itchy, red pustules that developed into a nasty rash that hung around for a couple of weeks. I finally had to see a doctor, who said it was probably caused by chiggers. But I thought chiggers are red, big enough to see and only live in forests. Apparently, I was wrong. Are there precautions I can take so it won’t happen again?

Adult chiggers are, in fact, red, but, at 1/20 inch, you’d need a magnifying glass to see them. Their youngsters, the larvae of these arachnids, are smaller still at barely 1/150 inch. They’re the ones that are doing all the biting.

Chiggers (Trombiculid mites) have many common names (harvest mites, red mites, red bugs) and are found throughout the world. In North America, they are more prevalent in hot, humid regions. They like areas where vegetation is heavy, such as forests, but also make their homes in lawns, near lakes and streams, even on golf courses.

When the insect’s eggs hatch and develop to the larval stage, they begin crawling along the surface of the soil, searching for food. Their diet isn’t particularly selective, and, unfortunately, includes humans.

Contrary to popular belief, chiggers neither suck their entrée’s blood, nor burrow into the skin.

Actually, chiggers use their piercing mouthparts to puncture the skin to inject saliva containing an enzyme that breaks skin cells down to a liquid form which the insect then can suck up. It is the saliva that causes the irritation. The pimple-like rash often does not show up for several hours after the bite.

A hot bath or shower, lathering with soap several times, should rid you of any insects still attached.

Besides being tender and itchy, the only danger of chigger bites in the U.S. is the possibility of a secondary infection from scratching the rash. In other parts of the world, however, chiggers can transmit scrub typhus, a disease which can result in organ failure, bleeding and death if left untreated.

Going forward, you’ll find that wearing loose-fitting clothes that cover your arms and legs will be a helpful deterrent. Consider applying bug spray containing DEET to your skin according to the label’s directions before your next round of weed-pulling.

For more information about getting rid of chiggers in your home and garden, go to the UF publication, http://edis.ifas.ufl.edu/ig085.

With all the stores decorating for the holidays, I’m beginning to think about the chores ahead of me. One is cleaning the ashes from the fireplace. Can I just take them to the garden and use them as fertilizer?

To understand why a person might want to do this, we want to remember those three numbers on every fertilizer package we buy. They are the percentage (by weight) of the three main plant nutrients — nitrogen (N), phosphorous (P) and potassium (K). And, because wood ash contains potassium and phosphorus, as well as magnesium, aluminum, sodium and calcium, it would seem a no-brainer to add it to our gardens. In fact, farmers in New England have been adding wood ash to their fields for many years.

But, as with everything else that sounds too good to be true, there are caveats to consider first.

Wood ash may contain all the nutrients plants need, but the quantity and quality are low and dependent on whether you burn hardwoods such as oak or softwoods like pine. The ash from hardwood is considerably more nutrient-rich than that of softwood. Therefore, you have no guarantee that your plants are receiving all the nutrients in the proper proportion for their needs.

Wood ash is alkaline and will increase the soil’s pH, while not as effective as lime. The recommendations for how much ash to use on a garden or acreage vary. So, if you plan to add large amounts of ash, you will also want to conduct regular soil tests. Additionally, avoid using wood ashes around acid loving plants like azaleas, gardenias and blueberries, or on areas where potatoes will be planted. Wood ash can promote potato scab.

Wood ash also will add nutrients to your compost pile and help moderate the pH if you compost a lot of acidic material, like fruit. Mix small amounts into your compost pile as you build the pile. The University of Florida urges that you use your judgement when adding ash.

Some organic gardening websites recommend using wood ash for pest control. Flea beetles can be deterred by a light dusting of a mild alkali like wood ash. The salt in the wood ash will kill pests like snails and slugs. Do not apply ash to newly germinated seeds, however. The salts will damage the seedlings.

Dan Sullivan, soil scientist with Oregon State University Extension warns, “Do not use ash from burning trash, cardboard, coal or pressure-treated, painted or stained wood. These materials can contain potentially harmful substances. For example, the glue in cardboard boxes and paper bags contains boron, an element that can inhibit plant growth at excessive levels.”

Though we may see wood ash as just the innocuous by-product of a cozy fire, we are talking about chemicals here. And as with all chemicals, natural or made in a lab, the first consideration is to protect yourself. Wear eye protection and gloves, just as you would handling any strongly alkaline material. A dust mask may be in order if the ash is fine.

So, as you watch the last embers of your first fire of the season, think of two things. Think of the bountiful garden you’ll have next spring, and remember that someone has to clean up that mess.

Paula Weatherby is a Master Gardener with the Duval County Extension Service and the University of Florida/IFAS. For gardening questions, call the Duval County Extension Office at (904) 255-7450 from 9 a.m. to noon and 12:30 to 3:30 p.m. and ask for a Master Gardener.