The month of January is an excellent time for planning this year’s garden. Looking back at last year, we knew what grew well, what we were happy with, and what did not do well or was a disappointment.
When deciding what we may want in next year’s garden it is a good idea to understand the difference between an annual, winter annual, perennial and a biennial in our northern Ohio gardens.
An annual is a plant that germinates from seed in the spring, grows vegetation, flowers and produces seed. During the winter the whole plant dies including the roots; however, in some annual plants the seed survives the winter and regerminates the following spring to start the process all over again. A good example of this is the common grass weed crabgrass.
Other annuals in which the seed sometimes survives the winter are Sweet Alyssum and Dusty Miller. All annual plants, if the season is long enough, will flower and set seed. There are some annuals, mainly vegetables that we may not see the flower or the seed such as radishes and carrots.
A winter annual behaves differently. This annual seed germinates in the fall and grows vegetatively during the winter. That’s right: These plants grow during the winter. In the spring they flower and set seeds. During the summer the entire plant, including the roots, dies; however, the seed remains viable in the soil through summer and germinates in the fall starting the whole process over again. An example of a winter annual is the common chickweed, these weeds often cause havoc in our perennial gardens.
An interesting anecdote: If we would reside in the state of Georgia, instead of Ohio, then the flowering Pansy would also be classified as a winter annual.
Perennials germinate from seed in the spring, produce vegetation, flowers and produce seed. During the winter the vegetative part dies out; however, the roots and the seed survive the winter. The following spring the parent plant grows back from the roots and the seed produces new plants. An example of a perennial is the common dandelion. Fortunately, or unfortunately, depending on prospective, our Ohio growing season often is not long enough to produce viable seed on some of our perennials. The good news, though, is that the roots survive the winter. Examples are Hostas, Sedum and Coreopsis. The best way to preserve our favored perennials is by protecting the roots through the winter by mulching.
Finally, is the misunderstood biennial. Biennials germinate from seed during the spring and summer. During the first growing season they grow only vegetation. During the winter the vegetation dies back; however, the root survives the winter. The following spring the plant regrows vegetation from the root and then produces a flower and seed during the growing season. During the second winter the whole plant dies, including the roots; nevertheless, the seed remains viable for germination the following spring and summer. The reason we seem to have flowers every year is because of overlapping generations. Hollyhocks and Foxgloves are examples of Ohio common biennials. A common biennial weed is the Garlic Mustard.
Now you know the difference between annuals, winter annuals, perennials and biennials. A good reason to understand these differences is weed control. Our Ohio weeds also fall into one of these four classifications.
Let’s look at our common grass weed, crabgrass, that is an annual. We know the seed germinates in the spring. Crabgrass germinates when the soil temperature reaches 55 degrees Fahrenheit. This means crabgrass preventer needs to be put down in the spring before we reach that magical temperature.
What about if we are dealing with a winter annual? If we put down a weed preventer for winter annuals in the spring and they do not germinate until the fall, by the time we reach autumn the weed preventer will have lost its effectiveness. This means for winter annuals, preventative weed control is placed in the fall.
As you plan the garden, you now have the knowledge not only about weed control, but also of what to plant, what will come back the following year, and what will bring you the most enjoyment.