Pre-soak for 24 hours in warm water and then sow in spring when the weather is reliably warm. The seed should have swollen up, in which case it can be sown, if it has not swollen then soak it for another 24 hours in warm water. If this does not work then file away some of the seed coat but be careful not to damage the embryo. Further soaking should then cause the seed to swell. One it has swollen, the seed should germinate within 2 - 4 weeks at 68°F, 20°C. As soon as they are large enough to handle, prick the seedlings out into individual deep pots and plant them out into their permanent positions in the summer. Give the plants some protection from the cold for their first few winters outdoors. Fast growing to 40'.