Monday, May 4th, 2009...3:38 am

Are Clematis and Lilacs Acid Loving Plants?

Clematis by love_child_kyoto (on flickr)

Clematis by love_child_kyoto (on flickr)

TheGardenLady received this question from Denys.

Are clematis and lilac plants acid loving plants?

Clematis likes soil that has a pH close to neutral (6.6-7.0). You have to add enough lime to ensure that your soil is not too acidic.  Generous amounts of bone meal and compost should be added to the soil. Clematis likes soil that drains well, so coarse builder’s sand should be added to soils that have a high clay content.

Lilacs also like a rich, well-drained soil with a neutral pH. They will grow happily in soil with a wider pH range- from 5.8-7.8 pH.

If the writer of this question is from the New England area where soils are often very acidic, soils will require modification for optimal lilac or clematis growth.

But do not try to change the pH of your soil by guessing. If you live in the US., contact your county agricultural extension service or your local Master Gardener Office for soil-testing information. You will get a soil testing kit that you will fill with soil for the test and when the results are returned, you will learn if your soil needs to be altered. The test results will be sent to you with instructions for altering soil pH to meet the needs of your plants. And if you don’t understand the instructions, you can visit the Master Gardener Office where the Master Gardeners will explain the instructions to you.

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  • Hi there, I saw a gorgeous plant at a person’s house and thought it was a clematis. She said it wasn’t and said a name like “boca via” or something. I tried to do a search and couldn’t find anything like that. It is a very tall plant in a huge pot with a trellis type thing to hold it up. Just beautiful! Any ideas what is was? Thanks. Rose

  • I would guess it was a Bougainevillia.

  • Although soil testing is valid as astm standard, soil conditions maybe change when the time passing.

  • I have a small backyard raised garden that was terribly depleted and empty when we moved in. I have since filled it with clematis, kerria japonica, hellebores, 2 star jasmine, and 3 irises. Are the plants compatible soil wise? Can I use the Seamax for them all or do I need to treat/fertilize them individually. I’m in New Mexico and I think most of the old soil was put in and I added some garden soil and have mulched heavily.

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