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| Raising Lavender from Seeds in Brazil |
Answered by: Conrad Richter
Question from: Eduardo Mattoso
Posted on: February 10, 2007
I have bought a few varieties of lavender seeds I was wondering which could be the proper way to sow them. I live in a tropical country (Brazil), I am aware that most lavenders do not flower around here. Anyway, I am worried about germination and dormancy. Could you please give some orientation in this way?
Some varieties of lavender can exhibit a type of seed dormancy caused by hard seed coats. The hard seed coat slows the infusion of water necessary to begin the germination process or they prevent the developing shoot and root from emerging. The english lavenders, Lavandula angustifolia, are especially susceptible to this type of seed dormancy. Other varieties such as the french lavenders (L. stoechas) and other species rarely if ever exhibit this form of seed dormancy.
Among the L. angustifolia varieties the condition of the seed coats can vary quite a lot depending on how the seeds were handled during harvesting and processing. Most commercially available lavender seed is harvested and cleaned by machines that cause enough incidental abrasion of the seed coats to weaken the seed coats and reduce or eliminate seed dormancy. However the extent of the abrasion often varies from seed lot to seed lot and you can sometimes encounter perfectly good seeds that are slow to germinate initially. Sometimes the rarer varieties of L. angustifolia are harvested by hand so the extent of abrasion is much less and the seeds are more likely to exhibit dormancy.
To soften the seed coat you can soak the seeds in water overnight before sowing. However small seeds like lavender are hard to sow when wet because they cling together when wet. When we encounter a seed lot that is showing signs of seed dormancy (i.e. the seeds are not germinating as quickly as expected) we move the seeded and watered seed box to a fridge for a week or more. This is a general technique for inducing germination in any slow-to-germinate species, not just the lavenders: it has the dual effect of softening the seed coats and providing a chilling period that many dormant seeds respond favourably to. This method does not work on dry seeds still in the seed packet -- it only works on wet seeds.