Mulch

Paul Burns, Garden Design & Education©

Mulch is an organic product spread over a bed to hold in moisture, inhibit weeds, and to provide a pleasing look to a bed. The most common mulches include pine straw, pine bark nuggets, and pine bark mini-nuggets. Any of these products work well, and selection is based on personal taste and availability.

A bale of pine straw covers 25 to 30 square feet of bare ground to a depth of 2 inches. The same bale will lightly cover about 50 to 60 square feet of existing pine straw to apply a fresh coat. Pine straw is the best ground cover for slopes because it knits together and doesn't wash like bark does. It is the natural choice for beds in and around pine islands where the pine trees will help to replenish the beds. Pine straw can break down quickly so pine beds look best if fresh pine straw is reapplied a couple of times a year. Don't remove the old pine straw, just top-dress lightly to improve the looks. This allows older pine straw to breakdown and add organic matter to the bed.

Pine bark nuggets will last longer than pine straw but may have a higher initial cost. A 3 cubic foot bag will cover 15 square feet to a depth of 2 inches.

Pine mini-nuggets are popular for the polished look they have. A 3 cubic foot bag will cover 18 square feet to a 2 depth. The same bag will cover 24 square feet of annual bed. I recommend using pine bark mini-nuggets to mulch annual flower beds because the mini-nuggets can be tilled into the soil as a soil conditioner when you change out flowers in the spring and fall. I rake off the good ones from the surface and reserve them for re-use, then till in the ones that are breaking down.

Cypress Mulch is EVIL!

Cypress mulch is popular because of its ability to withstand breaking down gives it the longest life. I personally think cypress mulch is EVIL! Although cypress mulch works fine in shrub beds, it doesn't breakdown to improve the soil. Over the years it can accumulate and upset the structure of the soil. It is hard to rake off a bed before planting annuals, and will accumulate in the soil, leaving you with a spongy mass that won’t hold water and dries quickly. Even worse, it is an ecological disaster. Cypress mulch is produced from entire cypress trees, cut and ground to produce mulch!

Pause for tirade from Paul: It is better to manage pinelands then it is to strip swamps of cypress. Pine straw and pine bark are the by-products of the Southern lumber industry which is an important source of paper and 2"x4"s. Using the bark prevents the waste of a material. I know some people feel we shouldn’t cut any trees, but the Southern pine forests are the best managed forests in the world. Georgia and neighboring states grow pines like Iowa and Illinois grow corn. The difference is that our crop takes 30 years instead of 6 months, and a heck of a lot more wildlife can live in our pines while waiting for harvest. Yes, I hate to see trees cut, and abuses can still occur, but we have gotten our act together with southern pines.

Southern cypress swamps are unique ecosystems that provide a great home for lots of wildlife. I can't see destroying stands of slow-growing cypress when replenishable pine is available.

Leaves can be used as mulch in the fall. Instead of burning them or bagging them, you can add them to the beds as a mulch which will breakdown to improve the soil. I usually use the lawnmower to shred and blow them into the beds, and then cover them with a light top-dressing of pine straw to keep them from blowing away.

Wheat straw is used as mulch to hold moisture to help germinate grass seed on a new lawn. Use 1 bale of wheat straw to lightly cover 1000 sq. ft. of bare ground. It isn't needed in over-seeding where you already have a stand of grass. Some people use wheat straw as a mulch in vegetable gardens at a thicker rate of a bale per 500 sq. ft.

Paul Burns, Garden Design & Education