Frost, Freeze and Green Tomatoes

 

From Franklin County, PA Master Gardener Facebook Notes (October 2013)

We are fast approaching the last frost free date of October 15 in Franklin County and many home gardeners, eager to either have homegrown tomatoes for Thanksgiving or loath to discard any possible foodstuff, are looking at their green tomatoes.

FROST VS. FREEZE

Frost,“ killing frost,” freeze warnings, a “killing freeze” - what is the difference? In casual conversation the terms frost and freeze are often interchangeable but there is a very real difference. Frost and freeze are two distinct phenomena. These terms take on significance when they are associated with the growing season.

FROST

According to the National Oceanic and Atmospheric Administration (NOAA), frost is the formation of thin ice crystals on the ground or other surfaces in the form of scales, needles, feathers, or fans. Frost develops under conditions similar to dew, except the temperatures of the Earth's surface and earthbound objects falls below 32°F. A frost advisory is issued when widespread frost formation is expected over an extensive area. Surface temperatures are usually in the mid-30’s. If a frost period is sufficiently severe to end the growing season (or delay its beginning), it is commonly referred to as a "killing frost."

Dr. Katharine B. Perry, North Carolina Extension Service, has compared frost and freeze conditions for protection of horticultural crops noting frost and freeze protection methods are based on preventing or replacing radiant heat loss.

Because frost is primarily an event that occurs as the result of radiational cooling - heat loss at night - it frequently occurs with a thermometer temperature in the mid-30’s. A radiation frost happens when a clear sky and calm winds (less than 5 mph) allow an inversion to develop. An inversion occurs when the heat radiating from the earth rises and causes the cooler air above to be pushed down, and temperatures near the surface drop below freezing.

Covering plants before the sun sets may be protection from frost as this can help retain heat near the plants.

 FREEZE

According to NOAA, a freeze is when the surface air temperature is expected to be 32° F or below over a widespread area for a significant period of time. Use of the term is usually restricted to advective situations or to occasions when wind or other conditions prevent frost.

Dr. Perry explains than an advective, or windborne, freeze occurs when a cold air mass moves into an area bringing freezing temperatures. Wind speeds are usually above 5 mph and clouds may be present. Attempts to protect plants are very limited under these conditions.

A "killing freeze" may be used during the growing season when the temperature is expected to be low enough for a sufficient duration to kill all but the hardiest herbaceous crops.

According to NOAA, freeze warning are issued during the growing season when surface temperatures are expected to drop below freezing over a large area for an extended period of time, regardless whether or not frost develops.

GREEN TOMATOES

We are closing in on the first average frost. (Check the date for your area.) Since it takes about six weeks for a tomato to go from flower blossom to ripe fruit, you should have pruned or pinched back your tomato plants in early-to-mid-September (cutting the growing tip off all the vines and any new blossoms to redirect the plant’s energy toward ripening up the existing fruit).

Oops! Okay, you were enjoying the weather and forgot. Now what? There's always fried green tomatoes or you can store them to ripen up later.

Kansas State also suggests roasting them for eating warm or cold, using in side dishes or freezing in small batches to use throughout the winter.

HARVEST AND STORE TO RIPEN

Pick and store your mature green tomatoes and let them ripen up on counter top or windowsill but not in the refrigerator. Ron Wolford, University of Illinois Extension horticulturist, notes that green tomatoes can be harvested before a predicted frost.

“You can tell when a tomato is nearing maturity by its light green, almost translucent, appearance,” according to Barb Fick, horticulturist with the Oregon State University Extension Service. “Tomatoes that are not in this 'mature green' stage won't ripen.”

Kansas State Extension Master Gardeners note that "not all green tomatoes will ripen off the vine. They must have reached a "mature green stage." Look for full-sized tomatoes with a white, star-shaped zone on the bottom end of the green fruit. Also, on maturing green tomatoes, skin at the blossom end may be beginning to change color from green to pink or red." Use immature green tomatoes in recipes such as salsas or fried.

Ron Wolford recommends removing the stems, washing and drying the fruit. Wrap each tomato in newspaper and place them in a single layer on a shelf or in a box. You can also put them in deep straw or just lay them in a box so that they are not touching. Check tomatoes every few days and discard any that show signs of rot.

Tomatoes will ripen satisfactorily in the dark, according to Fick, and sunlight is not needed; however, temperature is important. Storage temperature should range from 60 to 70 degrees. They will ripen over a period of three to four weeks.

Picking and storing the mature green tomatoes in mid-October means there's a good chance you can have some tasty, home-grown tomatoes for the Thanksgiving celebration.

CKagan, Master Gardener

**********

Interested in herbs? Looking for Gardening Gifts?

 Check out the Herb Sampler  description on this Blog  

SPECIAL Price reduction on Amazon here

The Second Edition Herb Sampler (2019) is available through Amazon. 

Egg Shells for Tomatoes

 

Egg shells (J. Harasewych)

Post-Easter, even after deviled eggs, egg salad, potato salad, and breakfast burritos you still have the shells. Questions about using egg shells in the garden to prevent blossom end rot in tomatoes brought many comments on the Master Gardener Facebook pages in addition to questions from relatives and friends. Here's some research-based information.

*Also, check the link below for a suggestion to provide calcium for backyard birds. (They make eggshells, too.) from Audubon. "Your breakfast discards can serve as vital nutrition for females as they make their own eggs." No research-information found on safety of artificially dyed eggs. If you use natural dyes all is clear. 

Blossom End Rot 

This is a common problem with both green and ripening tomatoes. This shows up as a black or brown sunken area at the end of the fruit. It is caused by low levels of calcium in the soil or inconsistent watering. An excess of nitrogen in fertilizer (the "N" in fertilizer numbers N-P-K, e.g. 5-10-5 = 5% Nitrogen, 10% Phosphorous, 5% Potassium, the balance is filler) supports foliage and can cause a problem.

If you had a soil test, and Calcium levels are in the medium (801 to 1,200 lbs. Ca/acre) or high range (>1,200 lbs. Ca/acre), soil should be good for growth. Calcium helps root and leaf growth and production of firm tomatoes.

Here is an informational article about egg shells and calcium from Christopher Enroth, Extension Educator, Horticulture, University of Illinois Extension.  

Enroth notes "For years, eggshells have been recommended as an amendment to soils and containers due to their high calcium content. Some gardeners who grow tomatoes swear by adding six or more eggshells in the planting hole, with the idea that the extra calcium will reduce blossom end rot of tomato fruit. Other gardeners compost their eggshells to add calcium to their finished compost. So do eggshells make a difference? Or is this egg wash?"

The Answer

Yes, adding egg shells does work but most gardeners miss a critical step. Thanks to Jerry Harasewych, one of my favorite researchers, for his step-by-step experiment and photos.

Egg shells need to be ground to release the calcium. They can be ground in a mortar and pestle but they are still chunky pieces. These larger pieces, although smaller than just crush shells, take a long time to dissolve and release calcium. 

They can be ground in a coffee grinder and the result is finely ground eggshells.  A research study in Alabama found finely ground shells performed as well as pure calcium and outperformed agriculture lime. 

Enroth also says,  "Don't have a coffee grinder but still have an abundance of eggshells? Another trick is to boil 10 to 20 eggshells and then let the concoction sit overnight. The next day strain the eggshells out of the water, and you have liquid calcium solution. Each eggshell adds four milligrams of calcium. Two cups of the solution per plant should be adequate. Apply about every two weeks. (Ref: Gillman, 2008)"

Water Calcium Connection

The Lackawanna County, PA, Master Gardeners share information about watering and calcium in tomato plants. 

"Blossom-end rot happens when a number of conditions come into place. The disease is especially prevalent when rapidly growing plants are exposed to wide fluctuations in water amounts. Calcium cannot be taken from the roots to the rest of plant and sustain healthy tomatoes. The fruit doesn’t have the necessary nutrient and the bottom of the tomato begins to rot. Other factors include a pH out of range and damage done to the roots from cultivation too closely. Heavy applications of nitrogen will contribute to blossom-end rot.

Other Tips

To manage blossom-end rot, take these steps:

Tread lightly around the roots of the plants to avoid damage.

Water consistently if there's a lack of rain, about 1"per week. Water slowly at the plant base.

Add mulch to your garden, this conserves moisture.

Use fertilizer low in nitrogen.

Do not spray any type of pesticide, as this is not a symptom of insect, bacteria, or fungi damage pesticides are ineffective on blossom-end rot.

Consider a soil test, this will give you a complete analysis of what your garden needs and will give you a head start for the next growing season."

** Special thanks to Jerry Harasewych for his grinding experiment and the photos.

 * Audubon link:

 https://www.audubon.org/news/give-nesting-birds-calcium-boost-saving-your-leftover-eggshells

Ref:From Univ. of Illinois  site:  Using Eggshells in the Garden and Compost

https://extension.illinois.edu/blogs/good-growing/2018-03-28-using-eggshells-garden-and-compost

~ Carol Kagan 

**********

Are you interested herbs? Check out the Herb Sampler on this Blog 

The Second Edition Herb Sampler (2019) is available through Amazon.

Heirloom Vegetables: Good Taste and Interesting Tales

Purple Calabash

[I now have a column in the Franklin County Free Press (online). There may be different topics covered there. Please visit their page. I am sharing my April 10, 2021, column here.]

Heirlooms provide a sense of history. The wardrobe from Great Aunt Rose’s attic, an antique carved chair, and a rusty tool from a local auction carry a sense of history, of the people who used them. This holds true for heirloom vegetable varieties.

“Heirloom seeds are usually more than 50 years old and have been passed down from generation to generation,” said Kathy McFarland, Baker Creek Heirloom Seed Company . “This means they come with fascinating stories and heritage from years past.”

While the stories don’t enhance flavor, shelf-life, or color they are a way to connect to our vegetable heritage. “Heirloom seeds have often been handed down as family favorites,” said Christine Mayer, Director at Wilson College’s Fulton Center for Sustainable Living. 

Heirloom varieties are open pollinated which means that, unlike hybrids, seeds you collect from one year will produce the same plants the next year. “Using heirlooms helps preserve the gene pool and assure that resilience from pests, diseases and climate are built into the system,” noted Mayer.

Many gardeners are drawn to stories behind the names. ‘Radiator Charlie’s Mortgage Lifter’  tomato came from radiator business owner, “Charlie,” who came up with a large, meaty, and productive variety that he sold during the depression. He used the money to pay off his mortgage.

Aunt Lou's  Underground Railroad

‘Aunt Lou’s Underground Railroad’ tomato has been traced back to Kentucky through Ripley, Ohio. The seeds were carried by an escaping slave as he traveled the Underground Railroad. The tomato is characteristic of those grown in that era.

Home gardeners have the luxury to choose what they grow. Many choose heirlooms for taste, size, hardiness, qualities for cooking, and color not found in hybrids; and savings seeds from year to year ensures the same plants.

The Japanese White eggplants, originally from Kyoto, Japan, are considered a Kyoto heirloom and are often found in home gardens and served in upscale restaurants. Their spongy texture quickly absorbs flavors such as ginger, soy sauce and miso as well as any sauces.

Japanese White Eggplant

Tomatoes have a wide range of shapes, colors, taste, and growing habit. Cherry, slicer, beefsteak, or canning types are available as are pink, orange, white and ‘Green Zebra’ striped varieties.

Heirlooms may not be pretty but gardeners seeking tasty fruit often find them the best. “Most heirlooms taste better than the hybrid and genetically modified produce because these have been bred and selected for generations based on how they taste,” said McFarland.

Pennsylvania heirloom tomatoes include Brandywine, reported to be introduced in 1885 by Amish farmers in Chester County. Other heirlooms include Amish Paste, Hahnstown Yellow, Amish Oxheart and Eva's Amish Stripe. 

The Hinkel Hatz pepper is named for fruits the size and shape of chicken hearts – a translation of hinkel hatz. It is a rare Pennsylvania Dutch heirloom dating to before 1880. The peppers are usually red or yellow and reported to have been cultivated for over 150 years.

Fish Peppers date to the early 1800's, grown by African Americans in Philadelphia and Baltimore. Black chefs made white paprika from the creamy white young pods for fish and shellfish white cream sauces, a secret ingredient passed down through oral history. The white paprika did not detract from the dish's appearance.

The rediscovery of these  peppers may be due to a barter - bees for seeds. In the 1940’s, Horace Pippin sought a remedy for his war wounds. Hearing that bee stings may relieve the pain, he bought bees from H. Ralph Weaver, in exchange for vegetable seeds which included the rare fish pepper. These seeds were made available to in the 1995 Seed Savers Exchange Yearbook.

Several years ago, I discovered German Strawberry oxheart tomatoes. Strawberry refers to the shape and not the size. Oxheart tomatoes are large (up to 3 lbs.), heavy and meaty with few seeds. Here are a few pictures.

CKagan, Master Gardener

**********

Are you interested herbs? Check out the Herb Sampler on this Blog  

The Second Edition Herb Sampler (2019) is available through Amazon.

°Brix- Measuring Sugar in Fruit and Vegetables

Black Cherry Tomatoes

Update: A post asked what is the sweetest cherry tomato. Aha. More poking around on the internet. 

A large tomato may have a Brix reading from 2.3 to 8.2; a small tomato from 4.5 to 11.7. In a tomato challenge one bag of Sungold won out over a different bag of Sungold.   These were the F1 hybrids. What I find is that there are three varieties that show up often: Sungold (9-10), Isis Candy (8-9) and Sakura (8.8) . (‘Rosada’is the sweetest variety tested in the UK - ‘Rosada’ is a baby plum variety with a Brix rating of 10.5.- Hard to find.)

IMPORTANT TO NOTE: Many factors influence a tomato crop and the crop’s Brix level. Variety selection and crop maturity are two key factors. Environmental factors, such as moisture, fertility, sunlight, and temperature also have an influence on Brix levels. 

This article has lots of good information. 

I am always amazed at what I learn when checking a fact for a post. In checking if the Black Cherry  tomato is open-pollinated before I posted I discovered a notation of a °Brix rating (note the symbol preceding the B).

And so I begin my "but I digress" internet time. Here's the interesting information I found. It is not a game or misspelling of bricks.

Degrees Brix (symbol °Bx) is the measure of sugar content in an aqueous solution. One degree Brix is 1 gram of sucrose in 100 grams of solution and represents the strength of the solution as percentage by mass. There is a digital refractometer that takes the measurements.

Drop of juice to measure sugar content

This measurement is used in fruit juice, wine making, carbonated beverage industry, starch and the sugar industry (think produce crops-corn, tomatoes, apples, citrus, melons).

At a Yara North America internet site (which piqued my interest even more to find out about this organization.) I found this explanation.

“Sugar levels in tomatoes:

°Brix is a measure of the Total Soluble Solid (TSS) content in the tomato or tomato product. The TSS in tomatoes is mainly sugars (fructose). A tomato juice, which is assessed as having 20 ° Brix, has 200g/litre of soluble sugars.

"Tomatoes for processing require a minimum °Brix of 4.5. This compares with an acceptable range of 3.5 - 5.5 in fresh tomatoes. The TSS of processed products is measured by refractometry.

"The °Brix content of the finished tomato product is largely controlled by the processor and manufacturing process. However, some processors do pay a higher price for higher dry matter tomatoes. In general, smaller, cherry tomatoes have a higher °Brix ratio and are sweeter than larger round or common tomatoes."

Penn State Video Capture

Ohio State has a more scholarly online article and Penn State has an online video of how to use a Brix refractor.

And this, my friends, is why, as a life-long learner, I find getting on the internet sucks up so much time. (2 hrs, w/photo finds and research)

Since this is research-based information, I am signing this as

~ Carol Kagan, Master Gardener

**********

Are you interested herbs? Check out the Herb Sampler on this Blog  

The Second Edition Herb Sampler (2019) is available through Amazon.

Soil Temps -Late Planting is Best for Home Gardeners

 

Home gardeners often plan to transplant seedlings after May 12th, the last estimated frost date for our area. More important than a date on the calendar is soil temperature. This year gardeners need to wait to allow the soil to warm up and the low air temperatures in the foreseeable forecast are consistently in the fifties or warmer.

"Soil temperature is a factor which few of us consider important enough to check before planting yet it probably is the most important factor affecting … seedling growth,” writes Dr. Jerry Parsons, Texas Extension Horticulturist. Warm soil allows plant roots to grow out into the bed quickly. planting yet it probably the most important factor affecting … seedling growth,” writes Dr. Jerry Parsons, Texas Extension Horticulturist. Warm soil allows plant roots to grow out into the bed quickly.

For the best start to the garden season, plant vegetables in the garden when the soil temperatures are best to do so. Plants are sensitive to temperature both above and below ground. If the soil temperature is not right transplants just sit there, biding their time until it warms up. This affects root development and can stunt growth throughout the growing season. Cool temperatures can also invite rot.

Tomatoes, one of our favorited homegrown summer crops,  are heat loving—not only should they not be planted in the garden until after danger of frost, it is best to wait until the soil temperature is warm. Memorial Day is the perfect time to plant tomatoes in much of Pennsylvania. If you plant too early, tomatoes will languish in the cold and may die during an unexpected frosty night.

During the week of May 11, 2020, in Fayetteville, Pa., the soil temperature in a sunny, raised bed was only 50° F. Soil temperatures will vary among different areas in a garden and between different yards. Soil in sunny areas and raised beds will warm the quickest.

Cornell University in Ithica, NY, publishes an up-to-date soil temperature map for the East Coast.

Use a soil thermometer and take the temperature at 2-3” deep around 10 to 11 a.m. Temperatures vary during the day with the lowest soil readings just after dawn and the highest in mid-afternoon. It is best to get a consistent reading over a period of four to five days.

The best temperature for transplanting local warm season crops is 60° to 65° F. These include tomatoes, peppers, cucumbers, cantaloupes, watermelons, pumpkins, and squash. Beans can go in at 55° to 60° F. but okra needs 70° F. or more. Penn State Extension Planting and Transplanting Guide.

~ Carol Kagan, Master Gardener

**********

Are you interested herbs? Check out the Herb Sampler on this Blog  

The Second Edition Herb Sampler (2019) is

available locally at Snavely’s Garden Corner or through Amazon.