Gardening: Shade trees are a great retreat from the summer heat

Jacaranda trees make for great shade trees.

The hot summer days we have been experiencing are perfect for picnicking. Sitting under a tree on a picnic blanket in the outdoors offers a refreshment from the Monday to Friday busyness that many of us incur.

Decent-sized, strong trees provide great shade and can be appreciated in many of our parks.

Bason Botanic Gardens on Rapanui Rd has some excellent examples of shade trees; the deep rich refreshing green of the Liquidambar and Liriodendron (tulip tree) are some of my favourites, along with the spectacular yellow of the golden elms.

These are all fairly big trees which are great if you have lots of room for them to grow.

If you ever have thought a shade tree in the back yard would be nice then it's probably during the hot summer days like we are having now.

A tree to dapple the strong sunshine, to provide some relief from the heat, a tree to sit under and read a book, for the kids to play under without getting sunburnt.

Bason Botanic Gardens on Rapanui Rd has some excellent examples of shade trees.

A shade sail could provide the same sun protection, but it does have not the same cooling effect of a tree.

The mass of water stored in a tree which travels from the soil into the roots, through the trunk and branches then evaporates out the leaves provides a cooling effect that is unsurpassed.

If you go for a deciduous tree as your selected shade tree, the tree will adjust to the light and warmth needs of winter.

During the winter months, when the last thing you want to do is block out the sun, a deciduous shade tree will have lost all its leaves, allowing light to pass through.

In situations where you need the tree to also provide privacy from neighbours or remove an object from view then an evergreen may be a better choice.

There is a great selection of trees that will provide excellent shade. The skill is to choose one that will meet the needs and requirements you want from it.

Things to consider are what size you would like, what space is available, whether you would like it to flower and whether you want something with good autumn foliage colour for seasonal interest.

These need to combine with the practical implications such as soil type, exposure to wind, frost, cold, coastal salt spray etc to ensure the tree's successful growth.

For a smaller town section, consideration needs to be made of the shade a tree may create for a neighbour, so smaller-growing trees or those that respond well to pruning will make a better choice.

Flowering cherries (Prunus) are a popular choice of shade tree.

There are a number of different varieties that all have slightly different growth habits.

The flowering cherry trees in Whanganui's Ridgway St in full blossom.

This means if it's a flowering cherry you want then you can usually find one that will grow to the size you have available. Kanzan is a taller growing variety with spectacular double pink flowers and forms a vase-shaped head, while Pink Perfection has a very similar flower but its growth habit is far more spreading so forms a better shade tree if it's width you need.

Jim's Delight is a relatively new release and only reaches 3m high. It is a little gem if you want a small shade tree for a tight corner. It has spectacular single pink blossom in the early spring as well as spectacular autumn foliage as the leaves turn shades of red and orange.

A top-selling flowering cherry tree would be Shimidsu Sakura.

This has an excellent spreading umbrella-shaped growth habit. It will grow about 4m high by 5m wide and, as well as being an excellent summer shade tree, it puts on a spectacular show in October with deep pink buds opening to double white flowers toned pink. Shimidsu Sakura also has a good display of autumn colours as leaves turn tones of orange and yellow before dropping.

Another excellent shade tree is the silk tree (Albizia julibrissin).

In flower at the moment, you will be able to spot them around the city with their mass of fluffy pinky-red flowers covering the trees. Hotter summers seem to improve the flowering of these trees.

The silk trees have distinctively soft ferny foliage which lends itself to provide good dappled shade from its naturally spreading branches. These trees, if left to grow, will reach about 6m tall and 5m wide but are easily pruned to a much smaller size. They grow quickly, so good shade can be established in three to four years.

Driving around the city I have also seen some magnificent Jacarandas in flower with their cool bluely purple blooms. These too can be kept smaller with pruning.

Jacaranda trees make for great shade trees.

Fruit trees can also make good shade trees.

A plum tree at the bottom of the garden can make an excellent shade tree, with a mass of white blossom in spring and an abundant crop of fruit around Christmas.

You can also consider a fruiting cherry. The blossom isn't as spectacular as flowering cherries, but the bonus of growing your own cherries is an option worth weighing up.

Evergreen shade trees tend not to change through the seasons and, apart from flowers and sometimes berries, they will offer a similar look year-round.

If you are wanting to use your shade tree as a year-round screen to offer privacy, then a evergreen tree will be a better option for you.

A lot of the larger-growing native trees make spectacular shade trees such as the pūriri, karaka, pōhutukawa and tītoki, but in a town section these will usually grow too big for the space available.

There are some good evergreen trees for smaller and town sections.

Leptospermum Copper Sheen forms a good shade tree when its lower limbs are pruned. It has a lovely weeping habit, and its coppery-burgundy red foliage makes it an attractive tree.

It also becomes covered in a mass of white flowers in summer. Very quick growing makes it a good option for quickly establishing privacy. It responds well to trimming and can also be grown as a hedge.

Some Michelia varieties form lovely shade trees. I say some, because there are varieties that simply don't grow large enough, and their habit is shrubby.

However, the dolstopa variety and its hybrids form good evergreen trees. These varieties will form a trunk with a rounded head of branches and foliage that will offer good shade from the hot summer sun.

A real feature of Michelia is an amazing display of highly fragrant, white flowers in the late winter and early spring.

So if you are feeling the summer heat, then consider a good spot to plant a suitable shade tree.

Have a good week.

• Gareth Carter is general manager of Springvale Garden Centre.