To main blog articles

You are currently browsing all posts tagged with 'green'.

Beautyberry: Insect Repellent?

  • January 5, 2011 11:18 pm

I love Callicarpas (aka beautyberries), blousy, deciduous shrubs with distinctive purple berries in late summer and fall.  I’ve just now learned that there is even more to love about them.   Some compounds in the plants have been shown to repel two species of mosquitoes:  

In bite deterrent studies, spathulenol, intermedeol and callicarpenal showed significant repellent activity against A. aegypti and Anopheles stephensi.

Callicarpa americana

Callicarpa americana

Here’s an article from 2006 (why am I just hearing about this?) describing the results of the science.   And here’s the published paper with details of the experiments and the resulting data.   Two species of Callicarpa, C. americana and C. japonica were tested and both showed repellent qualities.   The research began after a botanist in Mississippi mentioned a tradition of using leaves of the plant to repel biting insects.

“My grandfather would cut branches with the leaves still on them and crush the leaves, then he and his brothers would stick the branches between the harness and the horse to keep deerflies, horseflies and mosquitoes away,” said Charles T. Bryson, an ARS botanist in Stoneville, Miss. “I was a small child, maybe 7 or 8 years old, when he told me about the plant the first time. For almost 40 years, I’ve grabbed a handful of leaves, crushed them and rubbed them on my skin with the same results.”

It sounds to me that it’s worth a try as described above.  Don’t count on it to be available as a repellent yet, but grow a plant or two and grab some leaves.  My mother is quickly attacked by mosquitoes in her yard and I’ll be telling her to try this.   A couple of these shrubs grow in her yard.  I’ll try to remember to report back in the summer on the results of this non-scientific study.

C. americana (American beautyberry) and C. dichotoma (Purple beautyberry) are two of the most commonly grown species in our area.   C. japonica (Japanese beautyberry) is not as available and is said to have less showy fruit, or at least less persistent fruits. 

Purple beautyberry tends to be a bit more refined. There are are a few nice cultivars in the trade, including some with white berries.  Here’s a purple one that’s often seen:

Callicarpa dichotoma 'Issai'

Callicarpa dichotoma 'Issai'

 Welch’s Pink is a nice cultivar of American beautyberry:

Callicarpa americana 'Welch's Pink'

Callicarpa americana 'Welch's Pink'

The small flowers on these plants aren’t as noticeable as the berries, but are a nice summer accent until the big show later.  Birds don’t seem to like the berries so they last into fall when they kind of disappear.   Be sure to cut a few branches for interesting flower arrangements. 

Let me know if you find that they help ward off mosquitoes.

Let’s Talk About Mulch (baby)*

  • December 10, 2010 5:53 pm
 

Mulch. 

What is it really?  Pine needles, hardwood chips, pine bark, leaves, newspaper, gravel?

From Merriam-Webster: 

mulch: noun;  a protective covering (as of sawdust, compost, or paper) spread or left on the ground to reduce evaporation, maintain even soil temperature, prevent erosion, control weeds, enrich the soil, or keep fruit (as strawberries) clean

So, anything that provides the protective covering mentioned above is a “mulch”.   Inorganic and organic materials can provide that covering.  Some do different things, and all have benefits and drawbacks.  They also differ in price and ease of installation. 

First look at organic and inorganic mulches.  Organic would describe any material that can degrade into organic (carbon) compounds.  These compounds can then be used by organisms in the soil (plants, animals, bacteria).  Inorganic would include anything else. 

Organic mulches:

  • pine needles
  • bark/wood chips
  • straw
  • leaves
  • newspaper

Inorganic Mulches:

  • gravel/stone
  • landscape fabric
  • brick chips
  • rubber chips

Those organic mulches add nutrients to the soil.  Some, like chopped leaves and straw break down quickly; others, like pine needles, more slowly.  Generally, smaller pieces of mulch with greater relative surface area will degrade more quickly than other materials.  Landscape fabric, despite being inorganic, will break down over time especially when exposed to UV light. 

Of course when mulches break down they need to be replenished.  That’s where most of the inorganic mulches have an advantage.  Stone won’t break down (at least not in a landscape’s short geological time frame), so it won’t need to be replaced.  However, such mulches can “sink” into the soil below or appear to disappear as silt and organic matter build up in the material. 

Some mulches help with water infiltration, some inhibit it.  Layered newspapers will keep water from entering the soil until most of the sheets are fully wet.  Once the paper breaks down a bit this won’t be such a problem.  Landscape fabric also limits water infiltration unless there’s sufficient water to sit on the fabric and be pushed through the holes as more water falls on the surface (water’s surface tension causes it to bead up and roll off).  Large leaves can mat up and force water to find circuitous routes to the soil. 

Any material covering the soil will help prevent soil erosion.  Our Piedmont clay can erode easily and needs to be covered by some type of mulch.  When our clay soils compact (and rain can cause compaction) infiltration rates become the same as concrete or asphalt.  Water simply runs off, taking soil particles with it.  Soil particles are one of our biggest waterway pollutants.  If you see muddy water running into storm drains during or after storms, you are seeing pollution.

All mulches can reduce weed growth.  The covered soil keeps common weed seeds in the soil from light which inhibits germination.  However, weeds can still grow even with mulch.  Perennial weeds (weeds that live more than one season) that spread by underground stems or roots can travel through the soil and pop up in the mulch.  These weeds are most easily controlled with Roundup-type (glyphosate) herbicides or consistent removal.  Weed seeds can still blow or fall into the mulch and sprout right there.  These are easily removed when they are small.  Keeping little weeds from becoming mature, seed producing weeds is the best way to become weed-free. 

On stone mulches:  I will use this occasionally, but only when the look is appropriate for the design.  The most common use would be for a parterre type garden.  White or tan stones are commonly available and reasonably priced, but keep their reflective qualities in mind as they can be pretty bright in full sun.  Mexican beach pebbles are really popular, but they are quite costly here in NC.  I once used those for an indoor pool.   Here’re some pictures showing stone mulches:   

 
Boxwood parterres with gravel mulch
Parterre garden 

Indoor pool 

I do prefer organic mulches.  They look good and I love the fact that they add nutrients to the soil.  Pine bark is my favorite.  I have used decorative stone at one client’s home for some parterre gardens. 

I rarely recommend landscape fabric.  When used it is still necessary to cover it with another mulch–because the fabric is unsightly and to minimize its degradation.  So you really need to use two mulches.  On slopes the top mulch may wash away, revealing the fabric.  Like this photo shows it can get pretty ugly:

 
Exposed landscape fabric
Exposed landscape fabric

If you need something to stabilize the soil until plants spread out try an erosion control matting or a jute fabric.  Both are organic and will degrade over time.  Oh, and don’t try walking on a slope covered with landscape fabric and pine needles–you’ll slip unless you have crampons on your boots.  The only time I might use fabric is under stone mulches.  But be sure it’s not lumpy and the stone isn’t too thin or you’ll see it.

How much mulch do you need?  Well, this homeowner went a bit overboard:

Too much mulch

 

Run, it's gonna blow!

Most mulches are best kept at 2-4″ deep.  It’s important to keep mulch from becoming too thick at the base of most plants.  When the mulch is deep the trunk can rot.  Or trunks might sprout roots in the mulch making the plant much more vulnerable to freezing or drought.  Little chewing rodents can hide in the mulch with easy access to the base of a tasty plant if the mulch is too thick.
 
Stone mulches which also double as paths should not be more than 3″ deep as walking anything deeper can be really difficult.
 
One more mulch idea is to use living plants.  Groundcovers (including grass) do all that mulches do and they keep getting better as they grow.  You may not be able to cover all of your soil with plants so keep those bare spots covered with mulch.

 

 *I’ve had this tune in my head since I decided on this title!

 

Leave Those Leaves…

  • October 19, 2010 8:30 pm

well, sort of.  

There are plenty of reasons why keeping leaves on your property is a good idea.   Here are three:

  • First, removing the leaves is a waste of perfectly good mulching material.  Have you ever raked up those leaves to place at the curb, then headed out to the garden center for bags of mulch to put in your beds?  Yes, fresh new mulch looks great, but so can chopped up leaves. 
  • Second, municipal leaf hauling and composting costs our towns money.  Fuel, equipment, labor are all needed for fall leaf clean collection.  If your town doesn’t compost, the cost is even higher and extremely wasteful. 
  • Last, have you ever raked those leaves into a nice neat pile at the curb only to see them blown around the next day?  Or blocking storm drains because they are on the street side of the curb?  You did know they shouldn’t be on that side didn’t you?  How hard is it to drive down narrow streets with piles of leaves on the street? 

Personally, I think the only legitimate use for leaf piles is to please exuberant children.  Compost piles are a close second, but who has room for one that can accomodate all those leaves?  Think about it, trees use nutrients from the soil to build their leaves, the leaves senesce and fall.   Many valuable nutrients are still in those leaves.  We remove the leaves, robbing soil organisms of their own nutrition (from the organic leaves).  Finally, we add fertilizer to replenish the lost soil nutrients which the trees then use… ad infinitum.

So, what can you do with all those leaves?  They can be used to mulch planting beds, natural areas (so-called, but usually far from natural) and even lawns. 

First, chop them up.  This will increase the surface area of the leaves and allow decomposers to break them down more easily.  Whole leaves (at least large ones) mat up keeping water and oxygen from getting to the soil below.  This tends to create anaerobic conditions in which most soil organisms cannot survive.   Dry whole leaves tend to blow around and rarely stay where you want them (until they are wet and matted).  Mowers can be used to chop the leaves.   Mulching mowers are great when you can just leave the bits where you are mowing.  Mowers with regular side discharges will send the leaf pieces where you want them.  A bag (this usually gathers dust, doesn’t it?) can help collect the leaves to be placed where you want them.  You can also use a leaf shredder or chipper.  The leaves must be dry for the best results in both chopping and spreading.  So get out there before it rains but sleep in a bit to wait until the dew dries in the morning.

Finely chopped leaves can even be left right on your lawn.  Well, really IN your lawn between the blades.  The tighter your lawn, the finer you should chop.  You could run over the leaves several times with a regular mower but a mulching mower would work even better (you’ve been meaning to get one of those anyway, haven’t you?). 

Studies have shown that mulching leaves into your lawn won’t harm the grass and even increases the microbial activity in the soil which keeps the soil more open and porous.  Just be sure the leaf bits don’t cover the leaf blades.  Here in the North Carolina Piedmont our fescue lawns have just been overseeded, so watch out for those tiny plants.  Hopefully, you got the seeding done weeks before most of the leaves fall and the new grass has been mowed once or twice.  You can find more information on mowing new lawn grasses on page 15 of NCSU’s Carolina Lawns publication.

Be sure you don’t forget those regular lawn fertilizations, especially if you are applying leaf mulch.  Many of the microbes which will be breaking the leaf bits down into soil goodies use nitrogen while working.  They’ll tie it up and keep your lawn from using it (but release it again when they are done).  For our NC fescue lawns the fall fertilizations are the most important.  Hopefully you got yours done around Labor Day and will be ready for the Thanksgiving treatment (remember those two holidays plus Valentine’s Day for fescue fertilization).  Other types of lawns should be fertilized as recommend for the lawn type.  Again, Carolina Lawns has good information for all homeowners.

So, this year see how many leaves you can leave on your property.  Maybe we’ll be dodging fewer piles on city streets.  In a few years your landscape may be looking so amazing that your neighbors will wish they had more trees.

Earth Day, 40 Years On

  • April 22, 2010 7:29 am

I was asked to write a little something for Cary Magazine (a great local here in NC) in honor of Earth Day.

Check it out here and try some of the suggestions.  I included a few new ideas beyond the typical litter clean up and pleas to turn off the lights.

Compost Happens

  • April 16, 2010 8:08 am

I found a great video about composting.  Check it out and consider doing your own composting.  Try it in honor of Earth Day next week.

Compost Happens from Final Five Productions on Vimeo.

Watering: Part 2—Efficiency and a Healthy Lawn

  • April 13, 2010 4:12 pm

OK, so now it’s on to lawn watering. 

Just like with new plants, it’s important to water your lawn efficiently.  This will help ensure its overall health and its ability to withstand drought (we get those occasionally here in the NC Piedmont).  Efficient watering also saves water and makes us better stewards of our resources—you do know that lawn watering is always the water use people gripe about when water supplies are getting low.

Note—these quidelines are for North Carolina, USDA zones 7-8.

Things to avoid when watering:   frequent, light waterings; watering during the heat of the day, evening or night; allowing excess water to run off lawn areas; and overspraying hard surfaces.

Continue reading – Watering: Part 2—Efficiency and a Healthy Lawn

Compost Tea –Yea or Nay?

  • February 25, 2010 10:49 pm

I know everyone wants to do everything possible to become more “green” in the garden.  But sometimes we have to be careful about possible solutions that could cause problems.

Compost tea sold as a disease preventive is one of those potential problems.  In quite a few scientific studies aerated compost tea (most of those sold) showed no success in field studies on crops.  And actually, the teas can contain pathogens that could be harmful to humans.

Check out this link  (fixed) for more information.

There might be nutrients in the stuff, but don’t count on it to stop plant diseases.

As an alternative, use regular compost in your garden.   I know it’s so convenient to apply some kind of super liquid–easier to buy certainly–but compost spread in the garden is the best thing you can do for your plants.