Annuals are plants that complete their entire life cycle from germination to death within a single year. Biennials complete their entire life cycle in two years, mostly by developing vegetative growth during their first year, and then blooming, producing seed and then dying after their second year. Perennials are the many herbaceous plants that survive longer than just a few years or indefinitely.
As simple as these definitions seem to be, the plants that they describe are a bit more complicated. Some biennials can regenerate from the roots of plants that have already bloomed and died. Stems of some annuals can root where they touch the ground, to form new plants that survive for another year. Some annuals seem perennial if they replace themselves with their own seedlings.
Of course, none of that matters for the many biennials, perennials and self perpetuating annuals that get grown as mere annuals. At a time when ‘sustainability’ is a fad and trendy buzz word, it is ironic that so many bedding plants that could contribute more if given the chance to do so, continue to get discarded as soon as their primary season finishes. Most have more potential than that.
Self perpetuating annuals like sweet alyssum and nasturtium might only need to be groomed of old plants as new ones take over. Young nasturtium are rather efficient at overwhelming their own parent plants to some degree. Of course, subsequent generations will revert to feral plants. Fancier nasturtium will eventually become basic orange and yellow. Sweet alyssum will be plain white.
Many annuals that are actually perennials might survive through their off season if just overplanted with more seasonal annuals, and then regenerate when the weather becomes more favorable. For example, primrose from last season might be left in the ground as petunias take over for summer, but when the petunias finish next autumn, the primrose can regenerate for another season.
Such perennials regenerate more randomly than they grew in their primary season, and will need some degree of grooming and perhaps mulching.
The flowers may not last very long once cut, but cosmos, Cosmos bipinnatus, blooms so abundantly, that there might not be any shortage of new flower to cut and bring in to replace those cut a day or two before. Their pastel pinks and lavenders, as well as white, suit the Easter season perfectly. Their soft light green foliage is remarkably lacy. Mature plants are about two to four feet tall.
Pulling out cool season annuals that are still somewhat colorful is never easy, even if they are already deteriorating. There is always the desire to stretch their season as late as possible until they succumb to warmer weather. Only a few can perform all year, or get cut back to hide below other taller plants until the weather gets cool enough in autumn for them to regenerate and bloom again.
The same cooling weather that is initiating fall color is what finishes the zinnias that bloomed so colorfully through summer. Like tomatoes, they can stay out in the garden until they succumb frost if they continue to perform, and if the space they occupy is not needed for something else. There should be no guilt with replacing them sooner. After all, they are technically warm season annuals.
Just like African marigold that was featured earlier is actually Mexican, German primrose, Primula obconica, is actually Chinese. As odd as it is, the common name is an improvement from the former name of ‘poison primrose’, which was derived from the potentially irritating sap of the unimproved species before it was bred to be less toxic, as well as more colorful and prolific in bloom.
French Marigold might have been a more appropriate choice. It is the official flower of Dia de los Muertos on November 2. Some might say that the bigger and bolder African marigold, Tagetes erecta, is just as official. Both are Mexican, but as the names imply, most varieties of French marigold were developed in France, and most varieties of African marigold were developed in Africa.
The three most popular specie of Dianthus are sweet William, garden pink and carnation. Sweet William and garden pink are light duty perennial bedding plants that are often grown as annuals. Carnation blooms are more familiar as fragrant cut flowers than as home garden flowers. Then there is dwarf carnation, Dianthus caryophyllus, that combines the best characteristics of all three.
Gardening is not always fun. After diligently tending to warm season vegetables through spring and summer, it eventually becomes necessary to pull them up to relinquish space for cool season vegetables that grow through autumn and winter. It likely would be less unpleasant to wait for them to succumb to frost, but by that time, it would be getting late for the incoming vegetable plants.
The common name sounds funny, but it is easier to pronounce then than the Latin name. Mulla mulla, Ptilotus exaltus, is an Australian species that has been locally available longer than its limited popularity suggests. It may seem to be more peculiar than it is because it is grown primarily by specialty growers, who happen to grow many cool plants that should be more popular than they are.
They are really just smaller versions of the larger perennial dahlias that are grown for their big bold flowers and flashy colors. Technically, annual dahlias produce smaller versions of the same perennial roots that can survive through winter to regenerate the following spring. Yet to most of us, it is easier to purchase new plants in spring than to grow new plants from stored roots.
Tony Tomeo 