episode 51 | show notes & advice
Lots of the plants Sarah and Arthur love are grown from seed and for a full on cutting garden and beautiful pots and borders, you do ideally need to sow some seeds yourself.
In this episode, they share the basics so you can sow your seeds in the right environment, to have a garden that is full of annuals for tons of flowers and edibles all through the year.
In this episode discover
- Sarah and Arthur describe how they grow from seed and the different methods they use
- Why you should treat seed like gold dust
- Timing is key – Arthur explains how to sow with the season
- What Sarah is trialling this year at Perch Hill
- Sarah’s easy to remember 5 Ts for direct sowing success.
Sarah loves growing from seed, not only because is it so rewarding, but also because it is sustainable. Her New Year’s resolution is to question the sustainability of what she’s doing on a daily basis, growing plants at home from seed is both life enhancing and a very sustainable thing to do.
1) Rule of a baker’s dozen
Arthur’s advice is don’t try to grow 100s of seeds. Sow less, make it fun and really nurture the ones you sow.
He follows the rule of no more than a baker’s dozen (a baker’s dozen is 13. The most widely accepted theory is in medieval England bakers who cheated their customers with undersized loaves were fined or flogged. As they didn’t have scales, they’d throw in a bit extra for fear of coming up short).
2) Buy plug-in seedlings
Arthur prefers sowing larger seeds he can handle, like tithonia or cosmos. As he is short of time and space, to make it easy, for anything else, he’ll order in plug plants.
3) Sow with the season
If you don’t have a greenhouse – and have to use only windowsills (like Arthur), late sowing is safest. Most half-hardy annuals like zinnias and cosmos grow really fast, including edibles like basil. It’s best to sow these when you can go into the garden with a T-shirt on. Arthur’s main sowing period is from the middle of April into June.
Always start off with things that might take time to get going, antirrhinums you can sow in February/March. Anything that takes more than 3 weeks to germinate, sow in the middle of April.
You can sow cosmos even in the first week of May - they will catch up. The weather is better for them then and gets them off the windowsill and outside by the door sooner. This is important as they need light all around them, by the windowsill they’ll get leggy stretching towards the light.
4) Invest in a cold frame
Getting a small cold frame really makes a difference. It’s not so much the cold, it is the wind that can knacker little seedlings. The cold stops them getting leggy, helps them develop a strong root system and air circulation is good for preventing mould.
5) Follow instructions on seed packets
These days seed packets and catalogues give really good instructions on when to sow, not just ‘sow in March’ for everything. It can be hard to resist not sowing in February but most things can be started later. If you really want to get going now, go for half-hardy climbers like cobaea, which should be sown now so they flower in plenty of time before the frosts come and obliterate them.
Episode 41 tender perennial climbers has more on cobaea and other climbers to sow now.
1) Seeds are gold dust
Sarah advises thinking of seeds like gold dust. Most beginners think, the more I sow, the better results I’ll have. The reverse is true. Instead pour seeds out onto a white surface, like a saucer, and place individually into the tray so you can see them, then gently push them in or lightly cover according to the packet instructions.
2) Position all your seeds in one go
Sarah positions all the seeds that she is sowing and then gently pushes in or covers. This helps you stay on top of what you have done, especially if you get interrupted during the process.
3) Pricking out
Pricking out is when you move the baby seedling into its own pot so it can grow on without competing with its neighbour. Sarah uses a pudding spoon to scoop the seedling out and plop into another mini pot.
The key thing is to only touch leaves or roots very lightly and never touch the delicate stem.
4) Follow the stages
Sowing from seed is a bit like seeing a little child move from kindergarten to nursery, then primary school, then secondary school, university then out into life. Think about each potting stage like that, the seed tray is kindergarten, the 9cm pots are nursery.
For example, sow tomatoes in February into a seed tray, prick them out into 9cm pots, then into 1 or 2L pots then into the greenhouse or garden. It is tempting to skip the stages but don’t, as often plants need the feeling of restriction to thrive.
Some plants that you sow late might skip a stage or two, going straight from kindergarten out to life!
Jiffy Pellets and rootrainers
Some plants like cosmos will thrive having roots disturbed by pricking out and potting on. Others, like zinnias, will sulk. Plants known for not liking root disturbance are sweet peas, nigella, poppies and basil.
For these seeds, try growing them in Jiffy Pellets, which are made of peat-free coir. Place these in water to plump up (Arthur puts his in the bath, in a tray) and sow one seed into each pellet, then put into a 1L pot or if sown late in May the pellet can go straight into the garden, remove the membrane first.
Rootrainers are especially good for sowing plants from the legume family like sweet peas. Listen to episode 49 sweet peas for more on how to use rootrainers.
Trials at Perch Hill
Sarah has had some experience of using blockers to cut compost into blocks to plant seeds into, without great success, but is keen to trial again.
The main trial at Perch Hill this year is experimenting with different planting mediums. Trialling peat-free composts so far has had disappointing results. Trials this year will look at different mixes, the gold standard being accepted as: 40% loam, 40% leaf mould for drainage and moisture retention, 10% organic farmyard manure for richness, 10% grit or vermiculate.
Sarah is a big fan of sowing into gutters which you can get from builders’ merchants. Gutters are ideal to use in place of direct sowing, especially if soil is heavy clay like at Perch Hill. Great for plants that don’t like root disturbance and for successional sowing, i.e., parsley, lettuce and salads. Plus zinnias and poppies in the flower group. With pea tips or beetroot, Sarah will sow clumps of seed in stations along the gutter, again, not covering until all the seed has been placed. Then lightly pressing in or covering seeds with a light dusting of compost.
For planting out, simply place hands between plant 1 and 2 and gently push out of the mouth of gutter into a prepared row in the garden, then move the gutter along and push out the next plant, spaced about 10 inches apart.
It’s a good mind jogger for successional sowing, once a gutter has been planted, you go back and sow more seed. This is a nice way of ensuring a good of succession of plants all the way through the growing season.
Overwatering seeds causes rotting. Water seed trays, traditional or Jiffy Pellet, from the bottom, so sit them in water. If you use vermiculate, it changes colour when wet so can be a helpful guide to gauge when to water, but don’t use with seeds like panicum or nicotiana that need light to germinate.
Capillary matting is worth investing it as it holds moisture, reducing the amount of water needed.
Sarah also recommends getting a heated mat or propagator bench, to give warmth at the roots. This is good for chunky root formation – helping to produce stocky rugby players not whippy athletes – and better productive plants whether cut flowers or veg – cosmos or tomatoes.
Sarah’s easy to remember 5 Ts for direct sowing
Although Sarah does little direct sowing at Perch Hill due to clay soil, if you have cracking soil here are her top tips.
1) Timing – don’t sow too early, wait until the soil is warm. If weeds are popping up, it’s a sign nature’s doing her thing and a good time to direct sow.
2) Tilth – aim for a nice crumbly apple crumble topping.
3) Thinning – once seeds have germinated, go in and thin out – go by seed packet instructions but roughly one seedling every two inches.
4) Transplanting – trowel everything between the final distance, and with all the little seedlings in between, make another row from that.
5) Tie in – with almost all productive plants you will need to stake and tie them in – Sarah does this at the seedling stage.