Keep your garden growing - see what to plant right now

Growing Rosemary

View the Rosemary page

18 Apr 15 Peter (Australia - cool/mountain climate)
I am originally from NJ, USA. I now live in Costa Rica. When I lived in NJ Rosemary loved the summer months in that partially shady area I kept it, but once I brought inside before frost, it almost always got the powdery white on it as you describe. It is called powdery mildew and it can be easily controlled by mixing a teaspoon of baking soda in a pint of water...once dissolved, spray it on the plant every few days until the problem goes away. Mildew loves acid environments and the bicarb makes it alkaline, killing the mildew but not harming the Rosemary.
Gardenate App

Buy the app for iPhone/iPod, iPad or Android and support Gardenate

Planting reminders

Join 30,000+ gardeners who rely on Gardenate. Subscribe to our free planting reminders email newsletter


Home | Vegetables and herbs to plant | Climate zones | About Gardenate | Contact us | Privacy Policy

This planting guide is a general reference intended for home gardeners. We recommend that you take into account your local conditions in making planting decisions. Gardenate is not a farming or commercial advisory service. For specific advice, please contact your local plant suppliers, gardening groups, or agricultural department. The information on this site is presented in good faith, but we take no responsibility as to the accuracy of the information provided.
We cannot help if you are overrun by giant slugs.