What Does "Days to Maturity" Mean?

When to Start Counting

A row of seedlings, runner bean plants in pots in an organic nursery.
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What is Maturity, Anyway?

Most seed packets list either a "Days to Maturity" number or a Harvest Date. Many garden books and websites, like this one, will also provide this information.

Plant maturity is meant to tell you when the plant is ready to set fruit or flower. It is used with vegetables and annual flowers, to give the gardener some idea of how long their season needs to be, for the plant to successfully grow and produce in their garden. Perennial plants can be expected to take 2 - 3 years to mature. A gardener with a short 90 day growing season can look at a packet of melon seeds and see that the plant requires 110 days to mature. While there are ways to protect and coddle plants that need longer seasons that your area offers, the wiser option would be to look for a melon with a shorter growing season.

When Should You Start Counting the Days?

When you plant the garden? When you start it indoors? It can be somewhat confusing to glean when to start counting. Unfortunately, there is no standard definition. However, most sources work on the general agreement that

  1. If you start the seed indoors and transplant it into your garden, start counting from when you transplant. This holds true for transplant you purchase, also.
  2. If you direct sow it in the garden, start counting when the seed germinates, which is usually within a week or two of planting. Some gardeners prefer to wait until the true leaves appear, which should be within another week.

That said, these are only general guidelines. All kinds of cultural factors will impact the actual number of days to maturity. Weather is the biggest influence. Cold weather can cause seedlings to slow their growth and perhaps even stunt it. Plants that prefer cooler temperatures can bolt to seed quickly.

Too little or too much rain can also play havoc with young plants. All of these environmental factors can lead to plant stress, which also plays havoc with maturity dates.

We rarely have ideal growing conditions, but given somewhat reasonable conditions, you can expect the number on the seed packet to be an accurate gauge.