The seedy side of gardening
VIRTUALLY all flowering plants can be grown from their seeds. Transporting seeds was the major method of getting new species back to Europe during the 1800’s in the halcyon days of plant collecting.This included species of trees, shrubs, herbacous plants, annuals, bulbs and grasses.
Today most of the new varieties of plants that constantly keep appearing in the garden centres are derived form cross pollinating different plants in seculsion. This is done by clever plant breeders that hand pollinate one flower with another flower of the same species or even the same genus. They then note the parent plants and protect the pollinated plant so it can’t be subsequently pollinated by insects. They then harvest the seeds to grow on to see what new colours of flower or hybrids may have occurred.
So for example if a breeder is looking to produce a white daffodil he pollinates the palest yellow flowers with the other palest yellow flowers hoping to produce and even paler yellow or even white flower. This might be repeated over a number of years before he finally comes up trumps with a pure white flower. After this the plant will be grown on vegetatively to ensure that it stays true to the parent plant. Sometimes seedlings worthy of growing on just turn up by chance and this can happen in your own garden as well as in a nursery.
I have had white foxgloves in my garden for 15 years and they have self sown every year but I have never had any other colour other than white. The reason for this is that there are no other foxgloves in insect flying distance to cross pollinate them so they have come true to the parent plant and stayed white. This can never be guaranteed though and usually their is a variation ,even if slight, between the parent plant and seedling although species tend to come relatively true compared to named varieties. This may prove to be a positive for our ash trees that are struggling with the fungal dieback disease at present as there is a hope that the species is so diverse some trees will be naturally immune to infection.
You can have great fun in your own garden experimenting with seed collecting, sowing and growing on. You may even come across a diamond of a plant yourself. Annuals and perennials are probably the easiest way to get started with seed collecting and growing. This is because they are convenient to harvest and you will see flowers from annuals the following year and with perennials, at the most, in two years. With woody plants like trees and shrubs you will be investing a longer time to see much reward but growing an oak from an acorn into a tree has the potential to give years of satisfaction.
Collect the seeds when they are ripe, as a rule of thumb this is around two months after flowering but this can be variable so check the plant regularly. The time of year varies according the species. Seeds that are in berries or fruits will need to be collected before the birds eat them.
Pick the seed pods on a dry day and lay out somewhere dry and warm for a few days. If the seeds are not visibly falling out of their husks gentle rub them out. With seeds in berries squash out the seeds and wash off. Dry on some kitchen paper for a few days. Put your seeds in labelled envelopes for spring sowing. Some early setting seeds like Hellebores are best sown as soon as they are ripe.
Some seeds will self sow in your garden, like foxgloves, and as a rule I let them at it and move the seedlings later in the year If I require them rather than waste time collecting them.
When you get to sowing time use a seed compost and firm into seed trays or pots. Sprinkle sparsely over the compost surface with small seeds or place a couple of inches apart with handleable seeds. With very fine seeds sieve a millimetre of compost over them and firm again and water. With larger seeds push the end of a pencil or finger into the compost around two centimetres deep drop in the seed and cover. Be aware that some seeds benefit from pre sowing treatments such as soaking or stratification. Stratification is mixing seeds with a damp compost and exposing to the cold for a few weeks, the fridge will do just fine.