How to germinate Sweet Peas....

Summer-flowering varieties

Sweet Peas are actually very easy to grow. In milder areas, sowing in Autumn (Fall) or Winter produces earlier blooms and longer stems. If Winter is likely to produce frosts below -5°C, better to sow them indoors 6 – 8 weeks before the last hard frost is predicted. Protect your seeds at all times from mice and molluscs. We do not recommend sowing them in the soil, where you intend them to grow, during Spring because plant losses are greater. Spring sowing in containers is better.

How to sow:
* Sow one seed per cell of 5” Rootrainers, without the plastic cover;
* Alternatively, sow 6 to 8 seeds to a 5inch (12.5cm) pot;
* If space is limited sow densely in a seed tray and transplant when big enough to handle;
* Do not use bottom heat, 10C (50F) is the optimum for germination;

* Do not soak or chip the seeds as this may reduce germination; chipping is not needed but should do no harm;
* Use a coarse multi-purpose compost and ensure seeds are covered by no more than 1/4 inch (5mm) of compost after sowing;
* Do not firm the compost but water the pots with a fine rose;
* Place the pots in a cold frame or cold greenhouse and protect against mice and slugs. Germination should take place after two weeks;
* If you are sowing in late Autumn or Winter, your seeds may need a little gentle heat to germinate, e.g. on a kitchen windowsill, but do not use a propagator as it gets too hot;
* To reduce the risk of fungal infection, the compost should be kept slightly dry after the first watering;
* Make sure you move them to a cold greenhouse as soon as the young shoots break the surface of the compost, otherwise your plants will get elongated or ‘leggy’;
* Plants should be given as much light as possible.

How to look after your seedlings:
* Take precautions against slugs, snails, mice and birds;
* The seedlings will tolerate light frost and should be grown as hard as possible. Move them out of the glasshouse as much as possible and especially on sunny Winter days;
* Protect against damaging winds. When hard frosts are forecast, say below -5°C, your seedlings will need some extra protection. Close the frame’s lights and add some lagging (eg newspaper, bubble wrap, sacking etc). If the weather is particularly cold or the frosts prolonged, leave the lagging on to allow the seedlings to thaw slowly;
* Do not nip out the tips of Autumn-sown plants to encourage side shoot formation. This is because side shoots will develop naturally if the plants are grown hard enough and Winter root growth is preferred to shoot growth. For later sowings, when the plant is about 4 inches (10cms) high the growing point can be pinched out such that approximately 4 growing leaves remain.

Early-flowering varieties

In frost-free areas, it is possible to sow early-flowering varieties in mid or late Summer to have them flower during Winter. In colder areas, early-flowering varieties should be grown by one of these methods:
* in a heated greenhouse to flower from late Winter onwards by sowing in late Summer;
* in an unheated greenhouse to flower from Spring onwards by sowing in Autumn;
* outdoors, treating as Summer-flowering varieties to achieve earlier-flowering.

Want to know more?
‘Sweet Peas: an Essential Guide’ by Roger Parsons, published by The Crowood Press, available from us (can be signed) or any bookseller.

Roger Parsons, January 2014

...and if they don't grow, you can always pray!

© Roger Parsons Sweet Peas 2005-2014.
All Rights Reserved.