Hypericum - Growing Guide

Hypericum - Growing Guide

St John’s wort

We have stopped selling the popular groundcover Hypericum calycinum in recent years because it has become so prone to rust infections in the nursery and in so many people’s gardens. Despite cutting it down to ground level in spring (as you should) the rust problem will, sadly, not go away.

However, this problem is confined just to H. calycinum. The other varieties of this huge genus which we do offer come in a variety of sizes for different locations and positioning in the garden. Hypericums are grown, not just for their showy, cup shaped yellow flowers, but also, for their autumn colours and for their attractive berries. It is a matter of choosing what suits your garden; this list of what we grow is in ascending height order.

H. olympicum ‘Citrina’ is a small deciduous shrub achieving a height of only up to 10in. This makes it suitable for rock gardens or, perhaps, in patio planters. It has small green leaves and pale lemon-yellow flowers in summer.

Hypericum olympicum 'Citrinum' click for larger image
Hypericum olympicum 'Citrinum'
Hypericum olympicum 'Citrinum' click for larger image
Hypericum olympicum 'Citrinum'
Hypericum olympicum 'Citrinum' click for larger image
Hypericum olympicum 'Citrinum'

H. moserianum ‘Tricolor’ (syn. ‘Variegatum’) is a spreading semi-evergreen shrub growing to about a foot with a spread of, perhaps, double that. It has red flushed shoots and ovate mid-green leaves irregularly variegated with cream and pink. It flowers repeatedly right through the summer and on into autumn and has cymes of up to eight cup shaped yellow flowers. A sheltered position will give you the best of its foliage variegation.

H. x moserianum 'Tricolor' click for larger image
H. x moserianum 'Tricolor'
H. x moserianum 'Tricolor' click for larger image
H. x moserianum 'Tricolor'

H. androseanum ‘Autumn Blaze’ is a bushy deciduous shrub growing to around 2ft or perhaps more. It has large 6in long leaves and cymes of star shaped or cupped yellow flowers in mid-summer. Thereafter it really comes into its own with a splendid display of spherical red berry-like fruits that go black when fully ripe.

Hypericum androsaemum 'Autumn Blaze' click for larger image
Hypericum androsaemum 'Autumn Blaze'
Hypericum androsaemum 'Autumn Blaze' click for larger image
Hypericum androsaemum 'Autumn Blaze'
Hypericum androsaemum 'Autumn Blaze' click for larger image
Hypericum androsaemum 'Autumn Blaze'

H. x hidcoteense ‘Hidcote’ is perhaps the most popular, reliable and widely grown of all the plants in this large genus. It is very resilient in maritime or windswept situations and forms a dense, bushy, evergreen shrub growing to about 4ft in height with a similar spread in maturity. The flowers are large (2½in across) in corymb-like racemes of up to six flowers from summer and on into autumn.

Hypericum 'Hidcote' click for larger image
Hypericum 'Hidcote'
Hypericum 'Hidcote' click for larger image
Hypericum 'Hidcote'
Hypericum 'Hidcote' click for larger image
Hypericum 'Hidcote'
Hypericum 'Hidcote' and Cordyline australis click for larger image
Hypericum 'Hidcote' and Cordyline australis

H. lancasteri is a species found in Yunnan in China by Roy Lancaster some 40 years ago. We have only recently started propagating it in the nursery from stock plants (given to us by Roy himself) which now grow at Caerhays. At least in Cornwall, they are upright freestanding semi-deciduous shrubs which grow here to around 5ft. They are therefore woodland garden plants and not just plants for the shrub or herbaceous border. The cup shaped yellow flowers appear in cymes of up to 11 flowers in summer and, with us at least, well on into autumn.

Hypericum lancasteri click for larger image
Hypericum lancasteri
Hypericum lancasteri click for larger image
Hypericum lancasteri
Hypericum lancasteri click for larger image
Hypericum lancasteri
Hypericum lancasteri click for larger image
Hypericum lancasteri

Pruning Hypericum - Video Tip


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