Your seed packet said your radishes should’ve been ready for picking in 21 days. But, it’s now day 31.
What’s the deal? Bad seeds? Bad luck? Bad mojo?
, in gardening, there are no mistakes … just lessons. Some simple botanical detective work will get to the root of the problem.
The “days to harvest” and “days to maturity” are often used synonymously. Appearing in almanacs, calendars, catalogs, and on plant markers and seed packets, these days are basically estimations. It doesn’t mean you can pick pumpkins exactly on the 120th day. But you can guesstimate when to plant them in time for Halloween.
Vegetables are mature when you can start picking them, whether they’re fully formed or ripened. It’s not necessarily when they’re at their optimal size and flavor for eating. Brussels sprouts, carrots, cucumbers, peppers, and tomatoes can be picked at various stages, so full maturity can actually span several weeks. It depends on when you consider the crop ready for you to enjoy.
When you start measuring this time period depends on how the seed is started. If a carrot seed is planted directly into the ground, the time to maturity is the time between planting and harvesting the first carrot. So, if the seed packet says 60 days to maturity, you can roughly expect a harvest two months after planting.
Some gardeners measure the time to maturity from the day the seed germinates to the day the plant is harvested.
For seeds that are started indoors and then planted outdoors in the ground, time to maturity is usually measured from the day you transplant the seedlings to the day you pick the first ripe vegetable.
Seed packets provide only a single “days to maturity,” whether they’re sold in USDA Zone 4 (northern United States) or in Poway and San Diego (Zones 9a, 9b & 10a). However, our warmer weather and longer growing season mean that crops will ripen sooner.
You can use days to maturity to compare different varieties of the same vegetable. If you live in an area with a short growing season, plant varieties that have the fewest number of days to maturity.
When you transplant them, plants go through a brief adjustment process to get acclimated to the soil. This slightly slows down the maturity process. Directly sowed seeds will not have that issue.
Harvest and maturity times depend on a variety of factors: weather conditions, sunlight, fertilization, environmental stressors, soil conditions and pests. Combined with the variety of seed planted, and the wide range of climate zones, it’s easy to question the helpfulness of these approximate “days to maturity”.
Since many vegetables can be picked at various stages of growth, “days to harvest” might be more appropriate than days to maturity. You can harvest carrots at 3” long, or wait until they’re twice that size. Zucchini can be harvested anywhere from 6” to a foot long.
Some packets show “days to germinate” which is the number of days most of your seeds will sprout as seedings. It’s expressed as a range, such as seven to 14 days.
Some cool-weather crops, like cabbage, carrots, and radishes can be planted in fall or spring. They will grow quickly in spring, but much slower in the fall as the amount of sunlight declines each day.
So, how do you harvest crops in the winter? With an ice sickle, of course.
(Don’t think I didn’t hear you guys just now. I expected a few groans. I bet some of you even did an eyeroll.)
Farmers calculate Growing Degree Days (GDD) to predict when a flower will bloom or when a crop will reach maturity. “The basic concept is that development will only occur if the temperature exceeds some minimum development threshold or base temperature.” (Source: https://extension.psu.edu/understanding-growing-degree-days.) This information can even estimate plant and insect growth stages and predict the best timing of fertilizer or pesticide applications. GDD involves sophisticated mathematical formulas…but I’ll spare you guys the grief. Consult with a homeschool parent.
According to the Cornell University Cooperative Extension, “The optimum temperature for ripening tomatoes is 70 to 75℉. When temperatures exceed 85 to 90℉, the ripening process slows significantly or even stops. At these temperatures, lycopene, and carotene, pigments responsible for giving the fruit its typical orange to red appearance cannot be produced. As a result, the fruit can stay in a mature green phase for quite some time.”
Interestingly, for flowers, seed catalogs and packets indicate the blooming period, such as “July to September” or “early to late summer.”
Basically, your fruits and vegetables will be ready when they meet with your approval…which could be any day now.
Schmidt is a Poway resident and award-winning garden columnist with over 40 years of gardening experience.
