Buying Vegetable Seeds: Do’s and Don’ts

Solid References are Key

Start with the right references, such as New England Vegetable Management Guide. It is specially written for the New England climate, and pests. Keep it (hard copy or online) open while you order. Before committing to large orders, consult NEVMG crop chapters and talk with seed company representatives about size, color, and shelf‑life of produce. Keep a small on‑farm trial block for two to five new entries per crop.

HortScience published a free-access article on Vegetable Cultivar Descriptions for North America List 29. It is the newest national publication of vegetable varieties, and pulls together up-to-date cultivar names, brief trait notes (like maturity and disease resistance), and seed sources across many crops. These notes are useful for double-checking what’s on a seed order, and building a short list.

Lean on university disease‑resistant variety lists and tips. Cornell University's Vegetable Resources summarize resistance and how to use it, with links to variety trial results.

Matching varieties to Connecticut conditions, particularly days to maturity and frost window lets you choose ‘days to maturity’ that fits your farm’s frost‑free period. In addition, higher hills and inland sites run shorter in ‘days to maturity’ than the shoreline. Connecticut Vegetable Crop Calendar and freeze/frost tables such as National Weather Service (Fig. 1) are handy starting points, which you can then fine‑tune with your farm records.

Plant Trials

Trial on your farm. Keep planting notes and try out a few new varieties, in small blocks, each year. Your field data will be your most useful information when you reorder.

Disease Resistance

Put disease resistance at the top of the list. Resistant varieties are a proven, low‑cost cornerstone of Integrated Pest Management (IPM). Disease resistance varieties cut risk and can reduce sprays, but they’re not a silver bullet; integrate them with rotation, sanitation, and your other management tools.

For example, choose:

Pepper cultivars with Phytophthora resistance;
Pumpkins and squash cultivars with powdery mildew resistance; cucumber and cantaloupe cultivars with downy mildew resistance;
Basil cultivars with downy mildew resistance.

The key takeaway is to pick varieties with resistance to the specific diseases a) you’ve had, and b) those that reliably threaten Connecticut and the region.

A good way to learn more about common diseases is through the weekly pest alerts (sign up here if not already on the list). Plus, growers can submit samples to UConn Plant Diagnostic Laboratory.

Sourcing

Buy clean, high‑quality seeds and read the label. Check the seed tag. Look for germination rate, test date, lot number, and other purity info. Adjust seed rate if the germination rate is lower, for example seeding 10% higher if the germination is 90%.

If you’re an organic grower, USDA rules require organic seed when commercially available. If organic sources are found for a particular crop, document your search and keep records. Seed treatment must be allowed by the organic standards listed in your Organic System Plan.

Seed Treatments and Seed‑borne Disease

Hot‑water seed treatment can knock back seed‑borne pathogens like bacterial leaf spot in brassicas/pepper or black rot in brassicas and many others. You can treat on‑farm or submit seed for treatment to the UConn Plant Diagnostic Laboratory.

Ordering

Order early. Popular resistant cultivars sell out. Use substitutions that keep resistance traits and maturity similar. Plan for your microclimate. Coastal Connecticut has a longer frost‑free period than interior hills; use frost tables to dial in earliness.

Talk with fellow growers to swap notes on this season’s varieties, what thrived, what did not, and why. Share lessons learned, troubleshoot challenges, and get inspired for next season.

Do’s and Don’ts

Do:

Order from companies that focus on your region and collaborate with trusted researchers and plant breeders, consult with fellow growers on varieties that work for them, and consult;
Start with disease pressure. List your top three to five recurring diseases by field and choose varieties with HR/IR resistance that matches them;
Confirm seed quality. Check germ rate, test date, and lot number; ask suppliers about seed health testing for key pathogens;
Use the NE Vegetable Guide for crop‑by‑crop notes on variety traits, spacing, and IPM.
Hot‑water treat seed (or buy treated/clean seed) when seed‑borne diseases have been an issue, especially in brassicas and solanaceous crops;
Watch in‑season alerts for cucurbit downy mildew (cdm.ipmpipe) and weekly pest alerts;
Keep records by field and market grade; trial a few new varieties each season;
Follow organic rules on seed sourcing and document your search if organic seed isn’t available in the form/quality/quantity you need.

Don’t

Don’t rely on one tool. Resistant varieties still need rotation and sanitation and, when warranted, fungicides, especially for powdery mildew and downy mildew;
Don’t assume resistance is permanent. Pathogens change;
Don’t store primed/pelleted seed for years. Use it quickly or re‑test germination before planting next year;
Don’t save seed from F1 hybrids if you want uniform results next year; hybrids don’t breed true.

Crop‑specific Quick Checks

Peppers on heavier soils: Pick Phytophthora‑resistant peppers; if bacterial leaf spot is a problem, look for X10R (resistant to races 0-10). Improve drainage and plan a preventive oomycete fungicide program;
Pumpkins and winter squash:Choose PMR types ideally with homozygous resistance. Then follow a targeted FRAC rotation in July–August;
Cucumbers/cantaloupe:Add DM‑resistant cucumbers; watch the regional CDM map early‑summer and adjust fungicide timing;
Basil:Use Rutgers DMR basil cultivars to reduce losses to basil downy mildew.

Storage and Viability

Keep leftover seed cool, dry, and dark in airtight containers. Primed/pelleted seed loses vigor faster. Run a quick paper‑towel germ test before planting and adjust seeding rates.

Seed Saving

Seed saving can be a practical tool for vegetable growers to keep well-adapted open-pollinated varieties on the farm and manage seed costs. Identify non-patented varieties, healthy, true-to-type plants, and maintain reasonable isolation to reduce unwanted cross-pollination.

Before making seed saving part of the business, growers should consider legal limits on saving patented or contract-restricted seed, the extra time and equipment needed for seed processing and storage, and the potential to carry seed-borne diseases into future plantings.

Consult with resources like Legal Liability of Saving Seeds in an Era of Expiring Patents for legal considerations.

Resources

Cornell University. (2025). Disease-resistant vegetable varieties and tips on using resistant varieties. Cornell Vegetables. https://www.vegetables.cornell.edu/pest-management/disease-factsheets/disease-resistant-vegetable-varieties/

Cramer, C. S. (2025). Vegetable cultivar descriptions for North America, list 29. HortScience, 60(11), 2169–2189. https://doi.org/10.21273/HORTSCI19006-25

Goeringer, P. 2015. Legal Liability of Saving Seeds in an Era of Expiring Patents (FS-1000). University of Maryland Extension, College Park, MD. Updated July 20, 2022. Available at: https://extension.umd.edu/resource/legal-liability-saving-seeds-era-expiring-patents-fs-1000/.

Ng, M. and S. Ghimire. (2023). Crop planning calendar. https://ipm-cahnr.media.uconn.edu/wp-content/uploads/sites/3216/2023/12/Crop-Planning-Calendar-3.pdf

Rutgers University. (2019). Four new Rutgers sweet basil varieties are available for home gardeners (Downy mildew-resistant basil varieties). Rutgers University News. https://www.rutgers.edu/news/four-new-rutgers-sweet-basil-varieties-are-available-home-gardeners

Universities of Connecticut, Maine, Massachusetts, New Hampshire, Rhode Island, & Vermont. (2025). New England Vegetable Management Guide (2025–2026 ed.). https://nevegetable.org/

University of Connecticut, Home & Garden Education Center. (2025). UConn Home & Garden Education Center. https://homegarden.cahnr.uconn.edu/

University of Minnesota Extension. (2023). Crop and field planning tools for vegetable farmers. University of Minnesota. https://extension.umn.edu/vegetable-growing-guides-farmers/crop-and-field-planning-tools-vegetable-farmers

The information in this document is for educational purposes only. The recommendations contained are based on the best available knowledge at the time of publication. Any reference to commercial products, trade or brand names is for information only, and no endorsement or approval is intended. UConn Extension does not guarantee or warrant the standard of any product referenced or imply approval of the product to the exclusion of others which also may be available. The University of Connecticut, UConn Extension, College of Agriculture, Health and Natural Resources is an equal opportunity program provider and employer.

UConn Extension