Tuesday 25 November 2014

Heucheras, Heucherellas & Tiarellas: a few notes

Attending a Friends of the Botanical Gardens, Sheffield talk today, I picked up some useful tips on growing Heucheras, Heucherellas & Tiarellas from Vicky Fox of Plantagogo. I'm sharing my notes here because, a) it will help me remember, and b) in case they are of use to others.

How to tell the difference between these three hardy perennials
Heuchera: the leaves have veins and a wider range of colours; the flowers are bell-shaped

Tiarella: the leaves have 5 or 7 lobes and less variation of colour compared to Heucheras. The flowers are frothy-looking, individual flowers star-like.

Heucherella: yes, these are a cross between Heucheras and Tiarellas. The leaves have the shape and markings of a Tiarella and the colours of a Heuchera.

 Tiarella 'Morning Star' with 5/7 star lobed leaves

Growing and maintenance information
  • They are evergreen hardy perennials, grown more for their wonderful foliage than their flowers. Though the flowers are pretty too.
  • The darker/brighter the leaves of Heucheras etc are, the more likely they can take full sun. Conversely lighter/greener more shade. So...
    • Tiarellas do not like full sun
    • Heucherellas not so keen either
    • Golden/lime colour leaves great for full shade
  • The 'city series' (i.e. Paris, Milan) have a longer flowering period
  • They love growing in leafmold and bark - mimicking their natural habitat
  • They can take some dry weather, i.e. say a couple of weeks, but will need regular watering in hot summers (because we get those a lot...)
  • They don't like being waterlogged and will die quickly in these condition. So for heavy Sheffield clay soil you need add compost/drainage material. 
  • They aren't just for borders. They make great hanging basket plants, and there are some trailing varieties. And because they are evergreen and can take shade, you can have a all-year-round hanging basket.
  • They are great for containers (make sure they have good drainage), including shady mixed containers with say Heurcheras and Ferns.
  • They can be grown in pallets to make a vertical/living evergreen wall
  • They are fairly low maintenance. You just need to pick off any dead leaves, otherwise they can start to get woody/leggy. If they get woody/leggy, mound up some compost/leafmold around them in autumn and next spring you should get lots of new shoots.
  • Easy to propagate - snap off a section and pot up.
  • Don't bury the crown of the plant, as this can kill it off.
  • They can get 'Heuchera rust'. A sign is dimples on the leaves. If you turn the leaf over, you will see rust underneath. Remove any leaves and either burn them or put in general waste bins. Don't put them in home compost bins as it won't kill the rust off.
  • Even though the flowers are tiny, bees love these plants and will be all over them. So biodiversity - tick!

An enjoyable talk with lots of useful information - thanks Vicky.

Oh, and did I buy any plants? Silly question... I picked up Heuchera 'Paris' for a container I'm planting up, and Tiarella 'Morning Star' to go in the darker end of my Long Shady Border.

These are just my notes from the talk. You can pick up more growing information on the Plantagogo website, and you can follow them on Twitter @plantagogo and Facebook Plantagogo heucheras.

Heuchera 'Paris' with darker green veins on the leaves