Skip navigation.

Graham Rice on Trials

Updates on trials and awards from the Royal Horticultural Society by Graham Rice

Recent Comments

What a plant needs to get an AGM

Posted by Graham Rice on 23 Mar 2010 at 11:47 AM

Hosta 'Sum and Substance',AGM,RHS,Award of Garden Merit, Image: © Do not reproduce in any way without permission.What is it that makes a good enough to deserve an AGM (Award of Garden Merit) from the Royal Horticultural Society? Well, with the busy Easter plant buying weekend approaching this seems like a good time to run a reminder of the features that a plant needs in order to be worthy of this high accolade. And, as you’ll see, a plant really must be good to qualify. And those that do qualify carry the AGM cup symbol (below). So let’s look at what the RHS requires.

“It must be of outstanding excellence for ordinary garden decoration or use” The key phrase is “outstanding excellence”: whatever a plant’s ornamental or edible qualities may be, they must be of the highest standard.

“It must be available” That is, if you can’t actually buy the plant it can’t receive the award. The RHS PlantFinder is often the best guide to availability, although the sources covered do not include seed companies. Awards to new plants may be held back until they appear in catalogues or garden centres but that’s the rule: if you can’t buy it can’t get an award.

“It must be of good constitution” Plants must be fairly robust and resilient in normal growing conditions. Those which are weak do not qualify for the award.RHS AGM cup symbol,AGM,RHS,Award of Garden Merit, Image: ©RHS.

“It must not require highly specialist growing conditions or care” The point here is that weekend gardeners with no special horticultural skills should be able to grow the plants in their own gardens without spending a huge amount of time and effort creating special conditions. Of course, plants have preferences - some like sun, some prefer shade; some require acid soil, some don’t. But other than these basic preferences, plants should not require special treatment.

“It must not be particularly susceptible to any pest or disease” Speaks for
itself, plants which are especially prone to pests and disease problems are not good garden plants and so do not qualify for the award.

“It must not be subject to an unreasonable degree of reversion in its vegetative or floral characteristics” So, for example, variegated plants which repeatedly throw plain green shoots and double-flowered forms that regularly produce single flowers are not considered for an award.

If all six of these requirements are met, then a plant deserves an Award of Garden Merit. At present 7,426 plants have received the award – so there’s plenty to choose from. Look out for the AGM cup symbol (above) on plant labels, in catalogues, in books and online.

You can find out more about how plants are awarded the AGM on the AGM page on the RHS website.

The RHS website also features lists of AGM plants.

You can also search for AGM plants in different categories.


Ann W said:

I had never before seen the AGM symbol.  I have partially looked through the list you provided, and I am excited to have it as a resource.  <a>Plant and Garden Blog</a>

on 23 Mar 2010 at 02:22 PM

Graham Rice said:

You'll find it on labels and in many catalogues - I see you're based in the US and of course this is an award for British gardeners so is seen much less in North America.

on 23 Mar 2010 at 03:23 PM

uberVU - social comments said:

This post was mentioned on Twitter by Graham_Rice: RHS Trials and Awards blog New post: What qualities does a plant need to get an Award of Garden Merit from the RHS?

on 23 Mar 2010 at 09:47 PM

Farmville Gold Coin | Farmville said:

Pingback from  Farmville Gold Coin | Farmville

on 24 Mar 2010 at 05:34 PM

Farmville Gold Coin | Farmville said:

Pingback from  Farmville Gold Coin | Farmville

on 24 Mar 2010 at 05:34 PM

HeritageHydrangeas said:

The new 2013 listing of AGM plants is much appreciated. As a collector of Hydrangeas I would like a list of the Hydrangeas where the AGM has been rescinded. Is this available anywhere?

on 08 Mar 2013 at 06:02 PM