MeMo,
I have dry, sandy soil, too, and Oklahoma is well known for it's radically fluctuating temperatures and weather.
Lavender can be grown from seed, but it never does very well and doesn't seem to have the true qualities of those grown from cuttings. Your best bet is to buy some plants, then begin taking cuttings and start more plants. They root fast (about 3-4 weeks), and you can quickly fill your yard with these lovely plants. I like to grow mine along pathways so when I walk by them, the plants release their lovely fragrance from not only the flowers, but also their leaves.
Here is a list of the hardiest Lavenders & Rosemary's I've grown:
LAVENDER
English Lavender (Lavendula angustifolia) - it actually is a French lavender, too. :) I have a huge old shrub of this. It's about 10 years old, now.
Grosso - has big FAT spikes of rich purple flower heads - very tollerant of extreme temps and has done extremely well for me in this drought.
Munstead - small, gray leaves and lovely flowers. Can be used in cooking, too, like lavender sugar cookies. (YUM!)
Provence - the French grow this one for perfume and essential oil. Very tall. Blooms later than other lavenders and has very long flower stems.
Hidcote - Deep Blue-violet flowers and wonderful fragrance. I get at least two blooming periods from mine. There is one variety of Hidcote that has very big, very fat flower spikes. Amazing color and fragrance. (Can also be used in cooking)
ROSEMARY (Rosmarinus officinalis)
Rosemary is not very hardy. It is native to the Mediterranean and the warmer Euro countries. Most are hardy only to zone 8. A few varieties can take zone 7, IF you experience a mild winter, and IF they are well protected, and grown on a south facing area, but it is risky.
However, there are at least two varieties which I grow here in zone 6-6b that are more hardy than any others, although they still require some shelter and mulching in the winter.
Rosmarinus officinalis 'Madeline Hill', commonly labeled as 'Hill Hardy' in many garden centers and even sold as such by vendors at Herb Festivals. I am very happy with Madeline Hill. I bought mine in the Spring of 2005. It has grown into a big fragrant shrub, about 4-5 feet wide and 3 feet tall, so far. It is a great culinary rosemary too. It is such a beautiful plant. I hope it will bloom for me this winter.
Rosmarinus officinalis 'Arp' is the other good choice for zone 6 areas with winter protection. ( I grow them both in the ground and winter them over by piling mulch up around them.
My other Rosemary plants, that I have had for years, are grown in decorative pots and urns and are taken into the greenhouse in the Fall to winterover.
As with my Lavenders, I like to grow Rosemary along pathways so when I walk by them, the plants will release their lovely fragrance from their leaves.
Below is a Link to the GW Herb Forum for a topic that was discussed back in November 2005. The topic was about 'Madeline Hill Rosemary' and "Arp" and their hardiness were discussed. Several wonderful LINKS to go visit and enjoy. (If only we could smell the plants)
Interestingly, both of these fabulous varieties of Rosemary were developed in Northeast Texas by the same plantswomen, Madeline Hill. Yee-haa!!!
~ Annie
Here is a link that might be useful: 'Madeline Hill' Rosemary
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Hydrangea paniculata 'Grandiflora'
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