When you read through seed catalogs, you’re likely to find references such as “the best flavor in our taste tests” or “most consistent production in our trials.” Comparing cultivars of a specific crop for a determined set of criteria, known as “trialing,” is how seed companies decide which cultivars to sell. While reading seed catalogs is a favorite winter activity in many households, learning how to run a successful trial yourself can help take the guesswork out of which cultivars to grow.
Trialing different crops can provide you with a wealth of information, revealing which cultivars of zucchini are the most disease resistant, which red bell pepper plants produce the largest yields, or which beefsteak tomato really tastes the best. The information gathered will also reveal how well your plants respond to seasonal weather pressures, such as hot, cold, dry, or damp conditions. You can even trial seeds of the same cultivars from different seed companies to see which companies carry the best strains for your area and personal criteria.
Whether you’re a farmer looking to increase yields and decrease pest pressure, or a gardener looking for the tastiest cultivar to grow, knowing how to run a successful plant trial is a valuable skill. Now, we’ll look at how to conduct two different types of trials at home.
Plant Trial Within the Same Crop Type
For this type of trial, choose up to five different cultivars within the same type of crop. For example, if you choose to compare different red lettuce cultivars (Lactuca sativa), your list might include ‘Red Velvet,’ ‘Beleah Rose,’ ‘Flame,’ ‘Lollo Rossa,’ and ‘Merlot.’
While you can of course choose however many cultivars you’d like, keeping it to a handful will make your trial more manageable.
Make sure to clearly mark each cultivar throughout the trial, from seedling to transplant. Label a garden marker or wooden craft stick with the cultivar name, and stake it in front of each cultivar. Then, draw a simple map to note where each cultivar is planted in the garden. When trialing, redundancy will save you from the frustrations of a lost map or of faded, unreadable plant labels.
Additionally, you’ll want to start all seeds and transplant all seedlings on the same day and in the same conditions. Also, do your best to keep all growing variables the same for each cultivar, including weeding and watering. If you’re new to trialing, start with one crop at a time — the goal is to collect helpful information, not to get overwhelmed with record-keeping.
Plant Trial Within the Same Cultivar
While you may expect a cultivar to yield the same results no matter where it comes from, this isn’t always the case. Seeds adapt to their location, and different seed companies may have slightly different strains.
When trialing the same cultivars from different companies, be extra careful to correctly label your plants with the seed company name because the plants will likely look nearly identical.
With this type of trial, you’ll also want to take special note of seed size. If there’s a noticeable difference in size within the same lot, plant the largest seeds and compost the smallest ones. Larger, heavier seeds will often produce the best seedlings. Be aware, though, that this step only applies to trials comparing seeds of the same cultivars because different cultivars of the same crop may naturally produce smaller or larger seeds.
When the seedlings germinate, you’ll want to note how quickly they size up. Vigorous seedlings generally lead to healthier crops and heftier harvests. Seed vigor can be influenced by the previous year’s growing conditions, harvesting methods, storage conditions, and the age of the seed. Growing conditions, such as drought or excess rain, are often out of the seed grower’s control, but these adverse conditions can also reveal the strongest plants to save seed from.
If you’re purchasing seed from a company, you likely won’t know what conditions affected the crop. In this case, it may be worth running a trial multiple years in a row to see whether the cultivar is stable or if one year’s lot is stronger or weaker than the previous year. Ideally, you’ll find consistency from year to year.
Plant Trial Criteria
After you’ve chosen which cultivars or seed companies you’re going to include in your trial, set the criteria you want to measure. You can use our Free Downloadable Plant Trial Table to stay on track with your record-keeping during weekly garden observations.
You can use our Free Downloadable Plant Trial Table to stay on track with your record-keeping during weekly garden observations.
Do Multiple Plant Trials
In gardening, there are so many variables at play that you can’t rely on one season’s data alone. For faster-growing crops, such as lettuce, mustards, Asian greens, summer squash, carrots, and annual herbs, you can do multiple successions and trials per season. For longer-season crops (such as winter squash and potatoes) or crops that are planted once and harvested all season (such as tomatoes), it’s important to trial over multiple years in order to collect enough data to give you an accurate picture of the cultivars.
The Taste Test
The most important part of trialing may be the taste test. After all, we’re growing food to enjoy it, right? If you’re growing for yourself, you get to decide which cultivar wins. If you’re feeding others, it’s helpful to gather friends, family, and customers for the taste tests.
Create a scale system that asks people to rate each cultivar on a scale from 1 to 5. Gather information about texture, sweetness, bitterness, and overall taste. Because weather conditions may affect taste (heat can enhance the bitter qualities of lettuce and increase the zip in mustard greens, for example), do multiple taste tests over the course of your trial. This is especially helpful if you’re looking for the best cultivar for a particular seasonal slot, such as which lettuce produces a crisp and sweet flavor amidst summer’s heat and sun.
While the taste test is subjective, it’s the culmination of the trial. You may find you get great yields from a certain cultivar, but if it doesn’t taste good, why grow it? The goal is to find the sweet spot: cultivars with outstanding growing performance, high yields, and delicious flavor.
Review Your Data
At the end of the season, after the garden has been put to bed and all the taste tests have been concluded, take out your notes. This is the time to review all the information you’ve gathered and parse out its meaning. Add up the yields, review notes on pests and disease, and take stock of which cultivars you enjoyed eating the most. When you flip open your next seed catalog, let this information be your guide as you create your garden plan for the upcoming growing season.
Kate Spring is an organic farmer and writer in central Vermont, where she and her husband run Good Heart Farmstead. She loves photographing the garden almost as much as growing it; follow along on Instagram @goodheartfarmstead.