A Healthy Soil Diet -- Drought Resilience in Your Garden

Drought may be the “new normal” even here in New England.  This year, most of the state has been in severe drought, and 2010 and 2012 were two of the hottest growing seasons on record, with precipitation below 50% for some of that time.

Source: National Drought Mitigation Center

In our first blog post we highlighted the importance of deep watering, especially of new transplants.  While watering is critically important, there is a more profound leverage point in our landscapes: the soil itself.  

The health of your garden soil can make the difference between plants that wilt and turn yellow in summer, and a garden that stays vibrant with minimal watering.  The biggest factor in terms of how much watering you have to do is how much organic matter (basically, compost) is in your soil.  

For every 1% organic matter, each cubic foot of soil can hold 1.5 quarts more of water. Imagine a 1 cubic foot sized milk crate is a cubic foot of soil; these quart-sized water bottles illustrate just how much water that soil can hold:

Organic matter and water holding capacity

When it rains, or when you water your plants, you want the soil to hold onto as much of that moisture as possible.  

One of the gardeners we work with in Florence has been composting regularly for years.  Besides new transplants, she did not water once this season -- and her garden flourished.  When you dig into her soil, it’s like cutting into chocolate cake: soft, dark, and moist.  All that organic matter acts like a sponge, and also serves as a home for desirable microbes, insects, and worms which further contribute to a healthy soil structure.

Is there such a thing as too much compost?  It turns out there is, although opinions vary as to the upper limit on organic matter.  UMASS Soil & Nutrient Testing Lab says 8% in a vegetable or ornamental garden is the limit -- after that, things get out of wack due to too much organic matter. The extra compost acts as a greedy actor in the soil, holding on tight to nutrients and keeping them from your plants. During storms, these unused nutrients can leach into nearby waterways, causing algae blooms (that green color you see in lakes and ponds) that can be toxic to the watershed’s delicate ecology.  All that water-holding organic matter can also waterlog your plants.

Tracy Allen of the UMASS soil lab tells us that too much organic matter is like eating a diet of all fruit -- it can throw your whole system out of balance.

One of the best things you can do to be proactive about soil health for drought resiliency is get a soil test.  This is a great time of year to do it! The lab is less busy and hence the results come back quickly. And it also happens to be a great time to spread compost (and other nutrients and amendments), following their recommendations.  This way, your beds will be ready for spring planting.  You can get a test done for cheap ($21) by simply dropping off a bag of your soil at UMASS’ soil laboratory.  Here’s an example of what your results will look like:     

Soil Test Image 1 bar graph.jpg

Make sure you opt into the Soil Organic Matter percentage test.

Handy bar graphs tell you what range your nutrient levels fall into, and each soil test comes with further written interpretation and recommendations below. We can help you make sense of any questions you have reading the report.

Need more help learning how to make your soil as healthy as possible, so you can take off for vacation next summer and not worry about your garden during another season of the “new normal”?  Disturbed by the prospect of another season of drought and its effect on your landscape? Click on the title above to tell us what's on your mind. Give us a call if you want help getting it done.



Weathering the drought like the confident gardener you are!

Stressed about watering?

To be a healthy eater, you plan what you are going to eat, taking in quality food.  And you portion it right.  But every meal is not a calculation -- because that sucks the fun out of it.  And it isn't necessary.  There are too many factors, it's incredibly difficult to take them all in.

Watering is like eating right.

For plants, the factors are what season it is, how much light they are getting, how hot or cool it is, the drainage of your soil (does it pool up or dry out quickly?), and that specific plant's requirements.  

For example, raspberries and blueberries love water -- especially as they develop fruits.  They would love two inches a week during this time, which is the equivalent of a couple days of soaking rain.

If you aren't clear on what an inch of rain looks like, consider buying a rain gauge to place in your yard.  That way you can tell if that overnight rain reached the roots of your plants or was a barely quarter-inch sprinkle.  

All plants need water, but some can handle drought better, and some prefer to dry out before another deep watering -- like succulents.  

With plants, you can see when they need water because their leaves wilt, curl, and droop. When they look sad, that's a good time to make them happy with some water. 

If the plant is dry for too long the leaves brown and turn crispy. You don't want things to get to that point. Watering is one way to prevent die-back. 

In the garden, mulch is the ally of moisture retention.  Like a blanket, it keeps the soil cool and prevents evaporation from the surface.  Along with mulch, soil that is enriched with compost and organic matter holds much more water.

For every 1% of organic matter, your soil can hold 1.5 quarts more water per cubic foot

Composting and mulching are your friends.  

A dear friend who works with UMASS Agricultural extension gave me some sage advice about watering, true to her Latina/Catholic background.  She told me to water deeply when I first plant, lay down mulch, then give the plant my blessing (at which point she made the sign of the cross) and tell it that's all it's getting.  Of course, in times like these, you may want to give it some more.  The idea is that instead of constant, small waterings, which promote shallow, sideways root growth, you want the plant to put roots down deep to secure its moisture.  This will increase its resistance to drought.  It's also less work.   

Right now, the Pioneer Valley area is somewhere between moderate and severe drought, according to the Northeast Regional Climate Center.  These trying times call for more frequent (deep) waterings, sometimes every day, and especially to newly transplanted trees and shrubs. But, this is a bad time to plant anything -- transplants need more consistent moisture than established plantings.  

So water deeply, hold off on moving plants around, and most importantly, keep an eye on   them.  Part of gardening "expertise" is in the keen observation of your garden over time.  Your plants will let you know when they need water.  Happy gardening, and cross your fingers for rain.  

(And buy a rain barrel now if you don't already have one;)

What have YOU been doing for your plants to help them withstand this drought?  Noticed anything interesting about their response to the dryness of the summer, positive or negative? Tell us what you're seeing by clicking on the title above.

~Diego I.G.