Beyond PSHB: Trees For Bees

Noltea africana

Contemplating bees buzzing around a tree I wondered how the PSHB infestation might affect our dwindling bee populations. What trees might one thus consider planting to attract bees?

 

Bee Trees For Small Spaces

Besides feeding bees, Soap Bush (Noltea africana) has the following attributes:
 Attract butterflies and birds
 Twigs and leaves rubbed in water is a natural soap substitute
 It is a fast growing slender tree (height 2-6m tall)
 Does well in semi-shade and full sun
 Can be used as a hedge, a screen or a windbreak
Frost resistant
 Evergreen
 Flowers in spring and winter
Non-invasive root system
 Grows in clay soils, along streams and is ideal for seasonal wetlands

 

Bee Trees For Large Spaces

At the top of my list is the Common Karee. It is now classified as Searsia Lancea. Previously it was listed as Rhus Lancea. It is hardy, frost resistant and evergreen. I admire its many attributes:

A row of Common Karee at The Wilds

A row of Common Karee at The Wilds

 Natural soil stabilisation
Increases rainwater infiltration into soil
Reduces erosion
 Raises level of the ground watertable
 Provides a protective canopy for frost sensitive plants
 Is a good pioneer tree for currently barren land
 A beneficial fodder plant for animals
 With its low branches, it is a tree children can safely climb.

Common Karee is one the Big Five Trees for Climate Change in Gauteng. As an added bonus, it does not appear on FABI’s list of PSHB reproductive hosts. Nor of PSHB non-reproductive host trees. Thumbs up for this one so far. May it retain this resilient status!

 

Why is growing trees from seed important?

Rhus lancea seeds

Rhus lancea seeds

Both Common Karee and Soap Bush are easily grown from seed. If all you have is a small sunny spot on a balcony growing trees from seed may be something you wish to do. Saplings can be gifted, donated or sold.

Growing trees from seed is a significant long-term contribution to a sustainable urban forest. Many of the trees we purchase from our nurseries are marcotted branches from established trees. They are thus effectively clones of the parent tree. Clones do not adapt to changes. Trees grown from seeds are thus best suited to climate adaptation.

 

 

Solitary Bees and Bee Hotels

Solitary bee

Solitary bee

There are over a 1000 solitary bee species in South Africa. To provide homes for them in urban areas a bee hotel is another way in which to attract pollinators to our urban spaces.

Solitary bees are docile. They are therefore a delightful way for children to enjoy observing a diversity of bee pollinators. Every home and school should have at least one!

 

GREENPOP: List of honey bee attracting trees

GreenPop is a NPO which has extended its activities to Gauteng. Consider supporting their greening programme, in Johannesburg in particular. This is another way in which to contribute to re-greening our urban forest.

Of the 20 honey bee attracting trees listed in one of their blogs, the following are suitable for Gauteng’s climatic conditions:

Sweet Thorn

Sweet Thorn

African Wattle (Peltophorum africanum)

Wild Pear (Dombeya rotundifolia)

Buffalo Thorn (Ziziphus mucronate)

Sweet Thorn (Acacia karroo)

Dogwood (Ramnus prinodes)

Blue guarri (Euclea crispa subsp. Crispa)

September Bush (Polygala myrtifolia)

 

Of these, Sweet Thorn Vachellia karroo, previously classified as Acacia karroo, is another of the Big Five Trees for Climate Change in Gauteng that does not appear on FABI’s list of either PSHB reproductive hosts or PSHB non-reproductive host trees.

 

PSHB: Non-Reproductive Host Trees

Three bee pollinating trees included in Greenpop’s list that appear on FABI’s list of non-reproductive host trees are:

False Olive (Buddleja saligna); Tree Fuscia (Halleria lucida); Forest Elder (Nuxia floribunda)

If you have these on your property it is advisable to keep a close eye on them. To minimise the risk of infestation provide them with adequate nutrition this springRock dust is a good source of minerals that are taken up as needed.

As always, if your tree is infested, consult an arborist.

(Be aware that if you choose to plant PSHB infested trees you have an added responsibility. You may also incur additional expenses if they become infested at a future date.)

 

Sources and Resources

List of PSHB infested trees
https://www.fabinet.up.ac.za/index.php/research/7

Information on Trees
A useful website for information on indigenous plants and trees: http://pza.sanbi.org/
http://pza.sanbi.org/searsia-lancea

Searsia lancea


http://pza.sanbi.org/noltea-africana
http://pza.sanbi.org/vachellia-karroo

Greenpop’s blog on trees for honey bees:

20 trees for the bees this World Honey Bee Day

Solitary bees and bee hotels
http://www.beehotel.co.za/