Grevillea rosmarinifolia

Hello Australian Gardners:

I live in California and love growing grevillea. My question is this. How much rainfall do they need to sustain on their own. Mine took off last summer when it was 110 degrees, but I don't want to overwater if they don't need it this year. Our area receives 15 to 35 inches of rain annually.

Anyone know?

Thanks.

You probably will only need to water when it is hot and dry outside. Grevilleas don't like to be heavily irrigated. They like mildly acidic soil. Avoid saline soils and high phosphorus fertilizers.

Yeah, learned the hard way about phosphorus. Bone meal would be okay though, right? Or gypsum?

If you are growing the Grevillea Rosmarinafolia, it will grow just about anywhere. I found it to thrive in heavy clay soil. I have one here that loves all weather. It never gets watered unless it rains. I have planted a lot of our natives here and only water for the first year. If you get really hot weather, all the natives appreciate a drink when small. Once established, they are best left to survive on their own. I never fertilise mine .
I have found Grevilleas to be one of the best growers and survivors in the garden. So pretty too. The honey eaters love them.
Jean.

Thanks, Jean. I love this plant and it bloomed all winter here through hard frost and everything. I have also used Myoporum as a groundcover and it is wonderful. Just love Australian plants.

If you have a non-alkaline soil, they probably need very little of anything. In Hawai'i several Grevillea species have become naturalized, and they look healthy even on lava flows with very little soil!

Thanks for all of your input. they are lovely additions to the winter garden here and yet are not widely planted at all.

craxymary, gypsum isn't a fertilizer. Unless you have heavy clay that you want to loosen up a bit, it really isn't necessary.

Once your grevilleas are established, they will probably survive quite happily on little more than rainfall alone. They do better with a little supplementary water from time to time, but do well enough without it, provided you don't have drought conditions.

Funny, they did their best in 100+ heat and grew like crazy. We don't get summer rains, so I'll cut back the watering to once a month or so. That should work. THanks.