• AGM plants

    AGM plants have been through a rigorous trial and assessment programme. They are:

    • Excellent for ordinary use in appropriate conditions
    • Available to buy
    • Of good constitution
    • Essentially stable in form & colour
    • Reasonably resistant to pests & diseases

Hypericum trial under wraps

This year I have been lucky enough to pay several visits to The Sir Harold Hillier Gardens (SHHG), Romsey, Hampshire as part of a new trial of Hypericum, which is set to run until autumn 2017

Hypericum 'Rowallane' - photo by Matt PringleThere are more than 70 species and varieties in the trial which have been carefully assembled by David Jewell, Head of Collections at SHHG.

It is hoped that the collection will achieve National Plant Collection (NC) Status, to complement the existing NC held at Wakehurst Place, Sussex, and plants here in the trial are being assessed by the RHS for the Award of Garden Merit.  

All of the trial entries were propagated at SHHG and were planted out in the prepared bed during early June this year. Most have grown very quickly and are sufficiently established to go through their first winter without any protection.

However, there are still a few smaller plants that really need some shelter from harsh frosts this winter, so these have been protected with individual fleece cloches.
Winter protection for the more tender hypericumsAlthough 2014 has been an establishment year for the trial, members of the Trial Assessment Forum have already been impressed with the flower, foliage and decorative berries of many of the entries.

By early summer 2015 the plants should be well into flower and most should continue through until late September.

If you’re planning a trip to The Sir Harold Hillier Gardens you can also visit the trial which is situated just behind Jermyn’s House.

Useful links

Find cultivation details and supplier information for Hypericum

Discover more about National Plant Collections


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