By Bev Johnson

Master Gardener

For decades, we never had to worry about adding sulfur to our soil. “Dirty air” from atmospheric deposits fell using rain as a carrier. The 1990 Clean Air act forced the removal of millions of tons of sulfur emissions from U.S. factories. The result is that now we need to add sulfur to our gardens.  Between 2005 and 2010, the Iowa State University research showed that the yield of farm crops had a drastic reduction due to the lack of sulfur.

Adequate sulfur nutrition is vital in photolysis, and chlorophyl formation. It is also required in synthesis of some amino acids and protein in grains and for efficient nitrogen fixation. This is one reason gardeners should have a soil test. It, like nitrogen, washes out of the soil and needs to be replaced each year.  Plants use the oxidized form of sulfur. Elemental sulfur takes time to convert to sulfate that the plants can use. Clay soils hang on to their sulfur longer than sandy soils do.

One symptom of sulfur/ iron deficiency is yellowing on new plant growth. Sulfur is needed for plants to use the iron in the soil.

Horticulturists and farmers have been using leaf cutter bees for pollination since the 1960s for crops like blueberries, cranberries, and canola seed.

The leafcutter bee does just that. She gathers nectar, pollen, and small leaf cuttings into tunnels where they lay their eggs. The tunnel acts like a cocoon for the larvae to develop in. Compared to the honeybee, the leafcutter is usually non aggressive and solitary. They don’t have a caste system or a queen. The female leafcutter only lives about 6 weeks, the male just 2 to 3 weeks. This bee isn’t into honey production, they just want to reproduce.  They are most active in mid-summer temperatures and are more active than honeybees. The biggest difference is their homes. Both prefer to live and nest together but leafcutter bee shelters are huge, about 10 feet square. The leafcutter bees need space for the females to lay their eggs in individual tunnels. The tunnels can be bright blue. Shouldn’t be hard to spy one of those.  

Leafcutter bees are especially susceptible to a small wasp called Pteromalas venustus, and a fungal disease called Chalkbrood.

It seems every summer we get a cloud of smoke from wildfires. Believe it or not, there may be a silver lining in the chokey stuff.  According to researchers studying a family of chemical-compounds called karrikins that are formed in burning plant matter. Kerrik is the Australian native’s name for smoke. The researchers didn’t even have to invent a name for the stuff.

In nature, karrikins seem to help stimulate plant growth and germination after wildfires. In smoke-water prepared from smoke, karrikins also have growth inhibiting compounds. Scientists are working to isolate this compound to tap their growth promoting powers.    

These odds and ends are from the summer issue of The Furrow magazine.