Spring Cleaning Your Rain Garden, Wetland, or Native Landscape

Written by Kirk Mantay, Restoration Project Manager for the South River Federation

It's spring! And if you haven't stepped outside to see how your rain garden, vegetated buffer, or bioretention project are faring, you really should.  Now's a good time to get a jump start on spring cleaning.

1. Weeds.  March is a great time to get ahead of spring weeds and invasive species that actually emerge in late winter - including the purple deadnettle shown to the left.  The most important weeds to remove right now are invasive species known as "spring ephemerals."   These are species like Garlic Mustard, which emerges, blooms, sets seed, and dies within a period of a few weeks.   Other species - even desirable ones - might be sprouting from seed and if you don't want them to spread, early spring is the best time to cut or till them - before their root system gets any bigger.   As with most projects, "begin with the end in mind," which in this case means that your conservation landscape area should have no more vegetation in it than you'd like it to have during the peak of the growing season.  Just because you don't see later-emerging plants right now, remember, they'll be along soon to fill in the empty space.

2. Sediment removal.  If your property includes swales, wetlands, ponds, or rain gardens, spring is a good time to get rid of sediment and debris that may have accumulated over the past year.  Remember that most sediment will be composed of less than 10% pore space, and as a result, that "muck" is taking up serious space that should be occupied by water.  Stormwater guidelines generally advocate that sediment is removed any time it occupies more than 25% of the capacity of a wetland, pond, or rain garden.   Stormwater treatment research has shown that areas more than 50% full of sediment are usually "failing," either structurally or in their ability to treat pollution.

3.  Trash removal.  This is a no-brainer.  Spring is a great time to put on some gloves and remove trash, especially plastics and cigarette butts, from landscaping.  This season usually brings us several heavy rains, which in the South River tend to deliver a lot of trash downstream.

4. Inspect for erosion.  If any part of your conservation landscape was constructed for slope stabilization (living wall or other similar approaches), conveyance of water (rock-lined waterways), or water treatment (rain gardens, etc), please take a few minutes on a sunny day to inspect them all and make sure that tiny gullies called "rills" are not forming.  Look for exposed roots and other evidence of fast-moving water.  Small "dunes" or "deltas" of sediment immediately downhill are often a good sign that erosion is occurring uphill.

5. Inspect plants for damage.  During the growing season, this is an important activity that involves looking at buds, leaves, and stems for all sorts of insects, fungi, and disease that may be affecting your plants.  However, this time of year, it's much simpler.  You want to look for easily noticable signs of pest damage from vertebrates (voles, rabbits, and deer) as well as overwintering insects like the cedar bagworm and cane borers on blackberry, raspberry, and rose stems.   Physically remove as many as possible.  Be on the lookout for any survivors when the temperatures get warner!

Spring is the ideal time to tackle these very minor chores and give your native landscape or conservation area the best possible chance to be productive and successful during the growing season.  Good luck!