Growing Flowers – Annuals, Biennials, Perennials
Annuals are those plants that have a brief, though often glorious, life. In one year they germinate from seed, grow, flower and produce seed themselves. Some take most of the four seasons to do this but others may complete this cycle more than once in a year. Familiar examples of annuals are nasturtiums, Virginian stock, candytuft. (Some weeds reproduce themselves several times in one year also, groundsel is an example.) A true annual never goes on growing in the second or third year, but some hardy annuals are tough enough to stand the winter either continuing in bloom in mild winters until Christmas — or as seedlings when they flower the following year. Seed dropped in autumn from flowering plants will often lie dormant and germinate in spring. Mice and slugs take their toll of these, so many gardeners ensure an early crop of hardy annuals in autumn as well as in spring.
In seed catalogues, annuals are clearly divided into two groups, hardy and half-hardy. The latter are killed by frost and also need high temperatures before they will germinate.
Usually most of the half-hardy annuals take so long to flower in our climate that they have to be given an early start indoors in an artificially warmed spring or even summer temperature. Some seeds need a much higher temperature than others before they will germinate. For these, a heated greenhouse, a specially made propagator or some other warm place is necessary. On the seed packet containing half-hardy annuals you may read such advice as “sow under glass”. This means in a glasshouse, not in the garden under a pane of glass. Often a sunny window sill indoors provides a good nursery.
Half-hardy annuals should be planted out in the garden only when all danger of frost has passed. There are a number of plants which strictly speaking are half-hardy perennials, and which, in certain, though rare, circumstances will over-winter quite successfully. As most are killed by frosts, however, some half-hardy perennials are treated as half-hardy annuals, petunias are examples. These must be sown early enough in the spring to give them time to grow into plants mature enough to flower the same summer.
It seems to me that none of the popular annuals is very particular about(indeed some, such as nasturtiums, flower best in poor soil) though it should preferably be fairly well drained, sunny, well dug and broken up as finely as possible.
Seeds of hardy annuals can be sown at any time from March until May and some of the hardier types can even be sown in September. Examples of the latter seeds are: sweet peas, cornflowers, candytuft, larkspur, calendula, annual chrysanthemum. Generally speaking, the earlier seed is sown the earlier it will germinate and flower. Seed sown in September will probably flower in June; seed sown in March and April will flower from July to September and seed sown in May will flower from August to October. It is possible, then, to extend flowering time by saving some seed for later sowing. I always sow a few as late as June and early July, thus gambling on the autumn weather. It is surprising how often this pays off, and the bright spots of colour showing among the fallen leaves are doubly endearing. I use only the cheap packets of homelyfor this.
In a seed catalogue, you are likely to come across the terms, varieties, strains, hybrids, novelties, species. A species is a plant just as it occurs in nature, like the wild poppy. Every time it seeds the chances are that its seedlings will resemble the parent in every way. Very rarely a plant will vary from the specific type. The wild poppy did this once. A friend, who lived in Birmingham, noticed that a wild poppy plant was a different colour from the rest. He collected seeds from it, grew hundreds of seedlings, continually throwing away all the typical wild ones and saving only the ones that varied. These became known as Shirley poppies and they are a variety of the species.
Most nurseries offer the same variety of a plant, but occasionally a nursery will notice that a few of the plants are finer or more vigorous than the others. He will select these and breed only from them. These are called a good strain.
Hybrids are a cross between two species, just as the mule is the result of a cross between a horse and a donkey. If you save seed of a species, you will get plants which resemble their parents but seed you save of hybrids cannot be guaranteed to remain pure year after year.
Many of the novelties offered each year by nurseries are varieties, or, hybrids or more up to date, F. z . hybrids which mean that they are hybrids of a first generation cross. You cannot hope to save seed of these and see the same flower appear the following year. You are more likely to get an assortment of not so novel blooms.
Usually novelties are dearer than those which are established. You will see seed packets on sale almost anywhere and it is quite safe to buy them, for all seed manufacturers have to conform to regulations laid down under the Seed Acts. They are liable at any time to have their seeds inspected and tested.
Seeds vary considerably in size and weight, not always in proportion to the size of the bloom. Snapdragons or antirrhinums for example, give some 220,000 seeds to the ounce, mignonette 30,000 and zinnia 28,00o. So you can see that often a pinch of seed is enough for a small garden. Actually very few seeds are retailed by weight, most are measured.
If you want to grow large quantities of annuals for cutting or to cover quickly a large area (ideal for furnishing a new plot), you can buy many by the ounce or half ounce. This way they are very cheap. You can also buy mixtures, tall, dwarf, medium, suitable for children to grow or ideal mixtures to attract bees. I grow these mixtures myself and can recommend them.
Some seeds remain good for years but others quickly lose their vigour especially in a packet. Seeds are now marketed in a type of packet that ensures that they may be kept unopened for years.
People are apt to forget that seeds are alive. They must not be kept in an airtight tin. It is best to open the mouth of the packet and put it in a larger polythene bag through which it can breathe. Close the bags and hang them up away from mice.
If you have any seed of any plant left over from a previous year and you have doubts about its vigour, it is safest to sow it a little more thickly than usual or to sow a sample pinch indoors in a warm place so that it germinates quickly.
In nature,large and berry-like seeds for example often drop from the tree or bush on to soft mossy ground where they keep moist until the conditions are right for germination. If these are dried and packeted their vigour is lost and bad germination results. Many of these, like, should be sown ripe. So must some herb seeds, especially those of the parsley family or metalliferous, yet parsley itself keeps its vigour for three years!