This is a wonderful time of year, I still get enthusiastic when I walk through the glass house and see the seedling emerging. As a child I remember being transfixed by the magic of placing a round pellet of paper in water and watching it transform into a Japanese Garden.Today I am equally enthralled by watching tiny seeds develop into handsome plants, some of which live for hundreds of years.
What are seeds?
Before growing from seed, it is useful to understand how plants work. In the simplest form plants are made up of four essential parts:
- Roots: the anchor of the plant that are firmly in the growing medium. The roots absorb the water, nutrients and minerals from the soil and pass into the stem.
- Stem: it supports and spaces out the leaves and transports food from the soil to the leaves and around the plant.
- Leaves: in most plants these are the primary organs of photosynthesis; capturing light energy, along with water and carbon dioxide, and converting it into chemical energy.
- Flowers: produce the seeds. Some plants have bisexual flowers with both stigmas and stamens, others have separate male and female flowers and, dioecious plants, have flowers of one sex bourne on each plant.
Before plants produce seed, the flower of the plant must first be pollinated, which is why it is essential to have great biodiversity in your garden. Bees, flies and other insects are all used as vehicles for transporting the pollen from one plant to the stigma of another.
Once the pollen is on the stigma, it absorbs the sugar from the syrupy liquid which is on the surface of the stigma. The pollen, which is carrying three essential nuclei, then grows until it meets the ovary and onward to the ovum. Successful fertilisation results in the production of a live embryo which develops into a viable seed.
Seeds themselves are made of three parts:
- The testa, which is the outer protective layer;
- The endosperm, which is the food supply; and
- The embryo, which consists of the embryonic shoot (plumule), the embryonic.
Once the seed is mature, it must disperse. Seeds are often covered in a flesh, which may be soft or hard. This flesh might provide food for animals or be covered in burrs that attach to animals.
What essential ingredients are required for sowing seeds?
- Water: causes the endosperm to swell, split and dissolve the nutrients. The nutrients are then available to the embryo enabling growth. The growing medium needs to be kept moist but not wet.
- Oxygen: required to allow the seed to respire and break down food. Therefore, a light well-aerated growing medium is essential.
- Light: this determines whether the seed is sown on the surface of the growing medium or below. In general the larger the seed the deeper in the soil it needs to be sown.
- Temperature: every seed has an optimum temperature for germination. Often it is the change in temperature that triggers germination.
- Soil: the engine which supports the seed to full maturity. It is important to know what soil type the seed originated from; e.g. free-draining, acidic etc.
So how do you successfully grow seeds? Jekka's five top tips.
1. There are several factors that affect the germination of seeds but the best tip is to consider the plants native habitat. For example, if the plant is from a mountainous region, it will usually require cold temperatures to trigger germination, a sunny-position and free draining soil.
2. Sometimes we need to fool nature such as breaking a seeds dormancy by putting it in the fridge.
3. Be fussy about compost and avoid using garden soil or old compost. We specify the preferred soil types that suit the growing conditions for herbs in our Jekkapedia.
4. Sowing seeds is like cooking a meal. It is best to prepare everything before you start, for example, clean seed trays, labels to hand, compost mixed and ready and paper clips to hand to seal seed packets.
5. Probably my biggest tip, enjoy it. I have had many failures and successes over 30 years but the sense of achievement that I experience when seedlings appear and flourish into a new plant is very satisfying.
Where to start?
Whether you are an avid seed grower or are looking to start sowing this year, we have put a collection together of our best seeds for 2019: Jekka' 2019 top 10 culinary seeds. Please visit the Jekkapedia pages, by clicking on the plants below, for more information.
- Wild Rocket (Diplotaxis muralis)
- Dill (Anethum graveolens)
- Sweet Marjoram (Origanum majorana)
- Winter Savory (Satureja montana)
- Garlic Chives (Allium tuberosum)
- Coriander (Coriandrum sativum)
- Red Frills Mustard (Brassica juncea ‘Red Frills ')
- Cinnamon Basil (Ocimum basilicum 'Cinnamon')
- Japanese Parsley (Cryptotaenia japonica)
- Fennel (Foeniculum vulgare)
Reference: Seeds: The Ultimate Guide to Growing Successfully from Seed (Kyle Cathie, 2001)