I mentioned on Saturday that I’d sowed a lot of seeds this year. It may be of interest to some what I do with them if they germinate successfully.
I use Sylvagrow compost for both seed sowing and growing on. It is supposed to have a base level of feed in it, but it is surely not very much. Seeds that are quick to germinate grow fine for a short while then get pricked off into fresh compost. Seeds that are slow to germinate, or slow growing seedlings, will need to be liquid fed or they will not grow very much at all.
I sow most seeds in 9cm pots, pricking them off when they are at risk of being difficult to tease apart. In most cases, I prick them off into cell trays. I use 20 hole trays that are half the size of a standard seed tray. I find that if handled carefully I can get six to ten seasons out of them before they fall apart. Again, anything in the cell trays for more than a couple of weeks will need liquid feeding to keep it growing.
Sometimes I can fill a cell tray, tap it firmly to settle the compost, then using a pencil as a dibber, make a hole and feed the seedling roots into it. Sometimes the roots are too big and I effectively pot each plantlet separately into a cell.
Some seeds I sow directly into the cell trays, especially somewhat larger seeds like Morning Glory, Tagetes, Beetroot and spring onions. Big seeds like beans and courgettes I sow directly into 9cm pots.
Some things get planted out from the cell trays. Lettuce, beetroot, onions are examples. I find with the veg that the really vulnerable stage as far as my allotment is concerned is the period until the young plants are about an inch or two high. I don’t get many losses from cell grown plants, even if they’re quite small when planted.
Most things get potted on from cell trays into 9cm pots. The flower garden affords far more hiding places for slugs so I like to put out a somewhat larger plant in the hope it will survive better. It also means I can sow earlier and keep the plants growing in the greenhouse while it is still liable to be cold, even frosty outside. It will vary but many of these plants will be in the 9cm pots for four to six weeks so I use controlled release fertilizer pellets mixed into the compost to provide them with adequate nutrition. I bought a 25kg bag of Osmocote Exact 8-9 month granules last year and will get at least three season’s worth of potting from it, provided I can keep it in good condition. It is indoors, sealed tightly in its own bag, inside a bin bag. I generally mix 40 grams in 10 litres of Sylvagrow compost. You can get smaller quantities of it on eBay, where people have bought 25kg and broken it down into smaller amounts.
Once the plants are well established in the pots they get moved outdoors to harden off. I have carrying trays for the 9cm pots so moving them into the greenhouse if the weather is frosty or excessively wet or windy is fairly easy. Finding room is usually less easy. After a suitable period of hardening off they get planted in their final quarters.