The Importance of Soil Temperatures in Your Garden

It is the time of year when Georgia gardeners think about their Fall, cool-season gardens.   Leafy greens like spinach, leaf lettuce, and kale are all popular cool-season crops.  They don’t require the time necessary to make a “head”, you can eat the thinnings, and the varieties available are endless.

The Importance of Soil Temperatures in August
Lettuce in the Trustees Garden Savannah, Georgia

Often at the beginning of cool-season planting time, germination rates can be an issue.  “I have purchased new spinach seed and my germination rate is only about 50%.”  Or, “My arugula just did not come up at all.”  The problem might not be the seed quality but the soil temperatures, especially in a hot summer like we have been experiencing.  Seeds require a specific range of soil temperatures for best germination.

This chart from Cornell University shows optimum soil temperatures for germination of popular cool-season crops:

Crop Soil Temperatures needed for Germination Comments
Arugula 40 – 55° F May fail to germinate in warm soils
Lettuce 40 – 85° F Best germination below 70° F
Spinach 45 – 75° F May fail to germinate in warm soils
Kale 45 – 85°F
Collard Greens 45 – 85°F
Mustard Greens 45 – 85°F

If soil temperatures are close to the range extremes, the germination rate will definitely be affected.  These temperatures not only affect the germination rate but how quickly the seeds emerge.  For example, at 50°F spinach seed can take as much as three weeks to emerge.  At 70°F you could see emergence in just days.

Here are soil temperatures being reported by the University of Georgia Weather Network as of Tuesday, August 30th at 9:30 a.m.

Location Soil Temperature at 2″ depth
Ellijay  73.5 °F
Dallas  79.6 °F
Jonesboro  77.3 °F
Statesboro  83.0 °F
Tifton  78.9 °F
Valdosta  80.4 °F

Using the information shown, gardeners will have a difficult time growing spinach at this time in most parts of Georgia.

The lesson, be patient and monitor your soil temperatures.  Cool conditions are coming, I promise!

Happy Gardening!

August Gardening Chores for Your Georgia Garden

It is hot but there is work to be done in the garden!  According to UGA’s Vegetable Planting Calendar  :

Plant the following no later than the dates given:
—August 18: Snap beans and Irish potatoes (seed can be sprouted two to three weeks before planting).
—August 31: Cucumbers and squash; plant varieties resistant to downy mildew.

In order to calculate the planting date, determine the frost date and count back the number of days to maturity plus 18 days for harvest of the crop. If snap beans mature in 55 days and your frost date is November 15, you should plant on or before September 3.

August Gardening Chores for Your Georgia Garden
Chamblee Senior Center Garden

Start plants for broccoli, cabbage, cauliflower, collards, kale and onions in a half-shaded area for setting out in September.
Prepare soil for September to October plantings of “cool-season” crops. Apply fertilizer and prepare seeded so rains will settle the rows and make it easier to get seeds to germinate when they are planted.
If watering is necessary to get a stand, open the furrow for seed, pour in water, plant seed and cover. Use starter solution on the transplanted crops.
Water the garden as needed to prevent drought stress.

Beat Weeds While Feeding the Bees – A Guest Post by Josh Fuder

We cannot learn enough about the usefulness of cover crops in your community or school garden.  This week we are fortunate to have UGA Cherokee County Extension Agent Josh Fuder as a guest writer. He is teaching us about using Buckwheat as a summer cover crop.  Josh writes:

Each year I start my garden with grand visions of endless bounty.  Something happens around the first part of July though.  I’ve gotten full of squash and cucumbers even had a few choice tomatoes; basically I get too full to keep up with the invading army of weeds and pests.  The spring veggies are petering out as well as some of those early squash and cucumbers.  Then there is the stifling heat and humidity that makes going out in the garden almost impossible before 7 p.m.

Well this year I have a plan keep those garden beds from turning into pasture.  No, it’s not mountains of mulch or more hours with the hoe and tiller.  Enter Buckwheat (Fagopyrum esculentum), buckwheat is an unusually fast-growing plant grown for its grain like seeds in commercial agriculture.  In the home garden it is one of the best summer cover/green manure crops available.

Buckwheat Josh Fuder 3
The strip on the far left was outside of my garden prior to this year and was just grass, clover and weeds. It was tilled and seed was broadcast on April 17th, 2016.

George Washington and Thomas Jefferson were some of the first American farmers to grow buckwheat as they recognized its benefit in a healthy crop rotation.  Native to Russia the flexibility and adaptability led it to be grown on more than a million acres in the U.S. in the late 1800’s.  The grain is ground into flour and used in a variety of foods from noodles in Japan to breakfast staples like cereal and pancakes in the U.S.  I even had pillows made from buckwheat hulls when I lived in the tropical Pacific.  The pillows are meant to be cooler on your head because of the increased space for air.  I never got over the crinkling noise each time I would move however.

Planting Buckwheat

Buckwheat is easy to grow by simply broadcasting seeds and lightly raking them in.  A pound of seed is recommended per 500 square feet of garden space or 3 ounces per 100 square feet. You can’t really put too much seed down and since you will usually have to buy it in bulk from a local feed store; better to err on the side of too much.  Buckwheat does not require highly fertile soils but will benefit from modest levels of nitrogen.  Its many fine roots are well adapted at finding lower levels of Phosphorous and when crop residues are returned to the soil it becomes more available for other plants.

Germination begins in about 3-4 days and within 10-14 days the ground should be fully covered with emerging leaves.  This quick leaf cover will protect your soil from erosion, retain moisture and shade out those dastardly weed seeds.  Now just sit back, drink some iced tea and wait for the best part which is the floral display that begins 3-4 weeks after planting.  A large dense planting will literally stop traffic; my neighbors and passersby in my neighborhood have told me they always slow down to admire the five by hundred foot strip that I have along the road.

Same view on May 18th, 2016. Note the road on the left side of photo where neighbors slow down to take in the view.
Same view on May 18th, 2016. Note the road on the left side of photo where neighbors slow down to take in the view.

Buckwheat Care

Resulting honey is dark colored and distinctly different in taste from clover or wildflower honey.  The timing of flowering is also very beneficial to bees because the mid-summer is usually when there is less native forage available for bees.

Just remember that those prolific flowers that the bees are pollinating each turn into a seed if allowed to develop and dry on the plant.  So if you do not want buckwheat carrying over into your next planting it is best to cut the plants or till them under 2-3 weeks after flowering.  Some growers will cut it and leave the plant residue on the surface as mulch providing a pre-mulched area for new transplants.

Thank you Josh, for the information and photographs of your garden.

Happy Gardening!

Enjoying Your Fresh Tomatoes Vingenzo’s Style

As gardeners we know that fresh is best.  Not much beats a fresh tomato picked right from the garden.  Chef Michael Bologna would agree with us.  His restaurant, Vingenzo’s in Woodstock, Georgia, is based on freshness.  And, he loves a really ripe, fresh tomato.

Enjoying Your Fresh Tomatoes Vingenzo's Style
Chef Michael Bologna leading a cooking class.

Located in downtown Woodstock Vingenzo’s has won many, many awards including one of Atlanta’s Top 50 restaurants (Atlanta Magazine 2012).  The restaurant features traditional Southern Italian fare.  Sausage, mozzarella, pasta, sauces, and desserts are made fresh on-site.

Chef Bologna comes from an Italian family and he is very, very passionate about food.  He truly delights in seeing people enjoy his cooking.  He also enjoys teaching others how to prepare wonderful, fresh meals.

Enjoying Your Fresh Tomatoes Vingenzo's Style
Chef Bologna giving me a cooking lesson.

Chef Bologna has been invited and cooked at the famed James Beard house – twice!  Happily, he has agreed to share one of his favorite recipes with us.  It features garden ripe tomatoes, something we all have a surplus of right now.


Chef Bologna’s Fresh Tomato Sauce

2 T olive oil

4 cloves garlic, sliced thin

1 pint cherry tomatoes, quartered or 4 roma tomatoes, diced

4oz olive oil

salt & pepper to taste

5 fresh basil leaves


1. Heat 2T oil up until almost smoking.

2. Add garlic and stir.

3. When garlic just starts to show color add tomatoes and stir.

4. Simmer until juices are released from tomatoes and add 4oz olive oil.

5. Simmer for 10 minutes.

6. Remove from heat.

7. Season with salt and pepper and torn basil leaves.

8. Serve with spaghetti or angel hair pasta.


Enjoying Your Fresh Tomatoes Vingenzo's Style
Delicious meals don’t need many complicated ingredients.

If you haven’t grown tomatoes before, this recipe alone should inspire you.  You could try growing some late season tomatoes or visit your local farmer’s market.

Thank you, Chef Bologna, for sharing your talents with us.  And just for you…

Buon giardinaggio!  (translation:  Happy Gardening!)