Plants need at least eighteen essential nutrients to grow and develop. Deficiencies of any of these essential elements can cause reduced crop yield and quality. For instance, we know that a high protein content in bread flour is essential for quality bread baking while low protein contents in flour is critical for quality cake baking. Aside from genetics, soil fertility management has a big impact on protein content and types of protein in the wheat we use for baking bread or cakes as well as all other crops. Plant proteins contain, among other elements, nitrogen and sulfur. So having adequate supplies of nitrogen and sulfur in the soil for the crop being grown will affect the development of protein in plants. Sufficient amounts of these two elements will guarantee high grain protein content and bread baking quality, while low nitrogen and sulfur availability in soil can lead to low grain protein content and cause poor bread baking quality. Often plants exhibiting nitrogen deficiencies develop yellowing on their lower leaves.

Bottom leaves of tomato turning yellow often indicate nitrogen deficiency. Photo by dmp, UConn

A common problem that we often see in our vegetable gardens is blossom end rot in tomatoes, peppers and summer squash. When conditions are right, the fruits of these plants develop quickly and each new cell that is formed requires calcium. When not enough calcium is available to plants either because there is not enough in the soil or there is not enough moisture to move the calcium from the soil into the plant roots, a calcium deficiency develops and expresses itself as blossom end rot. Also, if you have seen internal brown spot in the potatoes growing in your garden, you may also want to check the calcium level in your soil. Typically, you would do this by checking the soil pH. Since limestone (calcium carbonate) is used to raise the pH as well as supply calcium, if your soil pH is in the 6s, there should be sufficient calcium present in the soil so if you are seeing blossom end rot, it would most likely be due to insufficient watering.

Blossom end rot on tomato. Photo by dmp, UConn

Potassium is another nutrient that crops like potatoes need in high quantity. Potassium not only influences potato tuber yield and size but also potato sugar concentration, hollow heart disorder, even coloring after cooking. Sufficient availability of micronutrients, such as zinc and iron, are important for plants growth and nutrition values. These micronutrients are also essential for human health, and you can often find them in supplements.

Tomato with possible potassium deficiency. Poor locules and thick, mealy walls. Photo by dmp, UConn.

How do we know if our soil is sufficient in these nutrients? Soil testing can give you an idea of your nutrient sufficiency levels in the soil and plant tissue testing can tell you if your plant is accessing these nutrients. Some potential issues that could impact nutrient uptake by your plants include low pH, excessive amounts of another nutrient, poor soil structure and drainage, compaction, and improper watering. For macronutrients, such as phosphorus, potassium, calcium and magnesium, soil testing is sufficient while for micronutrients, such as zinc, copper, boron, manganese and iron, we recommend testing both your soil and plants if a nutrient deficiency is suspected. If you observe poor plant growth and good plant growth in the same garden or field, it’s best that you take soil and plant samples from both areas and get the samples analyzed separately so that you can compare nutrient levels in these areas. Keep in mind that many diseases have symptoms that mimic nutrient problems so it is always a good idea to send photos of the problems you are seeing to the horticulturists at the UConn Home & Garden Education Center (ladybug@uconn.edu).   

Is this a disease on cucumber or nutrient deficiency? Photo by dmp, UConn

For soil testing for garden crops, you can take soil samples at any time of the year, but fall is best. While taking samples before seeding, transplanting of annuals, and greening up of perennials is important to ensure timely application of fertilizer and soil amendment to provide your crops with sufficient nutrients during the whole growing season, keep in mind, that samples submitted in the spring take longer to process because of the higher volume. If samples are submitted in late fall rather than in early spring, recommendations are likely to be identical and if amendments such as limestone, which takes 6 to 18 months to work, are needed, they can be added in the fall so they can start working. Any fertilizer would be added in the spring before planting.

If you notice deficiency symptoms in your plants, it is important to take quick action to try and diagnose the problem and apply fertilizers, soil amendments, or change your cultural practices to deal with nutrient deficiency issues. Although your plant’s health may have declined because of nutrient deficiencies, a rescue application of nutrients can alleviate symptoms and put it on the path to good growth.

Plant tissue testing is primarily recommended for commercial growers because at the UConn Soil Nutrient Analysis Lab, there are no recommendations for home gardeners, only commercial vegetable and fruit growers. For commercial growers submitting samples, it is critical to sample the correct plant part at the right growth stage. This is because the tissue test sufficiency ranges that are use to compare your samples are established for that specific plant part and growth stage for a given crop. For example, ten uppermost recent fully developed trifoliate leaves should be sampled from green beans in summer, fifteen compound leaves adjacent to the inflorescences should be sampled during midbloom for field tomatoes, and twenty-five mature leaves from new growth should be sampled during flowering – fruiting should be sampled for peppers. Prior taking your soil and plant samples, please visit University of Connecticut Soil Nutrient Analysis Laboratory https://soiltest.uconn.edu/ for guidance on when and how the samples should be taken. Feel free to call the lab at (860) 486-4274 if you are considering submitting samples for plant analysis. UConn also has a Plant Diagnostic Lab that can culture plants for diseases.   

Another important thing to remember regarding soil and plant tissue analysis is that it is important to send your samples to your local labs. This is because different labs use different testing procedures that are calibrated for soil types specific in their region and the plants grown in these specific environments. The standard sufficiency levels established are therefore different by state and by region. For example, there are many different soil test procedures being used in the US for soil phosphorus test, however, only modified Morgan testing procedure is used for CT soils due to specific characteristics of our soils in CT.

The bottom line for home gardeners and growers is to do your best to ensure your plants receive the correct amounts of nutrients as well as water to be able to supply the nutrients to our plants. Routinely monitor your plants for insects, disease problems as well as nutrient issues. We are here to help you so feel free to contact the UConn Home & Garden Education Center (www.ladybug.uconn.edu) or UConn Soil Nutrient Analysis Lab (www.soiltest.uconn.ed) if you need help or have questions.

Haiying Tao, Ph. D. Dept of Plant Science LA, UConn

The last few years certainly have been a challenge for many of us.  One unexpected consequence of the pandemic? Many who were quarantined at home decided to become gardeners.  Seed companies reported a boom in sales during the pandemic and, unlike other trends, (zoom cocktails, sourdough starters or dress shirts with pajama bottoms), it looks like gardening is here to stay.  To those new to gardening and to those more seasoned gardeners, we are here to help you every step of the way.  

We are the UConn Home and Garden Education Center, which is made up of three branches; the education center; the soil nutrient analysis laboratory; and the plant diagnostic laboratory. The education center is your first point of contact, where you will be greeted by horticultural consultants Dennis Tsui, Pamm Cooper and Marie Woodward.  Our mission is to answer your questions about anything related to home gardens and landscapes.  Our goal is to give you the best science-based response. In addition, we often rely on our other two branches for information, but that’s just the start of the services they provide. 

Dawn Pettinelli

Good gardening begins with knowing all you can about your soil, and The UConn Soil Nutrient Analysis Laboratory, headed by Dawn Pettinelli, Associate Cooperative Extension Educator, provides home gardeners a means to test the fertility of their soil and, through a comprehensive report, receive environmentally sound fertilizer and lime recommendations. 

Dr. Nick Goltz

Identifying the cause and nature of plant problems is often the key to maintaining healthy gardens and landscapes, and that’s where Dr. Nick Goltz, plant pathologist, comes in. He heads the Uconn Plant Diagnostic Laboratory and is an expert in diagnosing plant problems including diseases, insect pests and abiotic causes.  Dr. Goltz has a passion for plant health and integrated pest management, (IPM).  He especially enjoys working with homeowners to find holistic and comprehensive solutions for any plant problem they may have.

The three branches of the center are available to gardeners year-round.  To access our services, you can reach us by phone, (860-877-6271), by email, (ladybug@uconn.edu), or you can visit the center the Radcliffe Hicks Arena, 1380 Storrs Road, unit 4115, Storrs, CT. Our hours are Monday- Friday 8:30am -4:30pm.

Collecting and Submitting Samples

One of the most common questions we are asked is how to collect samples that are of good diagnostic quality.  Each laboratory website has detailed instructions on how to do so.  For the Soil Nutrient Analysis lab, there is a page with instructions on how to submit a soil sample at:

Soil Sampling Instructions

The plant diagnosis laboratory has a form with instructions on how to collect plant sample at the bottom of the submission page: 

Plant Submission Form

Samples can be mailed in or brought into our center during our office hours, (see above).

Emailing us with a question?

If you’re emailing us with a question or problem, it can be helpful, (but not necessary), to include a few photos with it.  This can help us determine our response. 

To learn more, you can visit our website: http://www.ladybug.uconn.edu/ where you will find the latest news, blogs and fact sheets about all things for your home garden.  We are ready to help make your home garden a success year after year. 

From this past Thursday morning until last night, the UConn Home & Garden Education Center, the Soil Nutrient Analysis Laboratory and Master Gardener Coordinators and Volunteers staffed our booth at the CT Flower & Garden Show. We weren’t sure how big a turn out to expect as in the past we have found that the more severe the winter, the greater the show attendance – probably because folks really needed encouragement that spring was on the way. This year, however, despite the warm winter, the show was packed! We must have performed more than 250 free soil pH tests and answered hundreds of gardening questions. The large number of soil pH tests was obviously due to the fact that most soils were not frozen solid – in fact there are many areas that only have frost in the top inch of soil – and that’s only on colder days.

Answering questions at the Flower Show

There were a lot of vole and deer control questions and many folks wanted suggestions for dealing with some of the diseases their vegetables, especially tomatoes, had been plagued with last summer because of all the rain. Moss in lawns was also a frequent topic of discussion and many visitors have heard of the boxwood blight that is infecting these lovely evergreens and wanted to know more.

The CT Flower & Garden Show has a lot to offer, from incredible landscapes to a multitude of vendors of largely garden related items, to the creative arrangements by Federated Garden Club members. I think I counted over 200 exhibitors in this year’s flower show program! The work that goes into some of the landscape displays is awe-inspiring! Years ago a company I worked for had an exhibit in the Boston Flower Show and the amount of time, effort, gardening expertise, and physical labor that went into designing, growing and setting up a landscape display left a team of us exhausted but happy with the outcome.

The CT Flower Show also gives local plant societies a place to introduce themselves to potential new members and give folks advice. One could find out information on African violets, bonsai, rhododendrons, orchids, carnivorous plants and much more. Representatives from UConn’s EEB Greenhouse and Invasive Plant working group were there to share their resources.

The theme for the juried Federated Garden Clubs of Connecticuts floral arrangements was ‘The Fabulous Fifties’ and there were so many creative, fun and artful entries it was hard to pick favorites, never mind winners. I would have had a tough time deciding who the awards should go to as all the entries were wonderfully creative.

Here’s some that caught my eye!

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The above 3 pictures taken by Clinton Morse, UConn EEB

Till next time,

Happy Gardening!

Dawn