The summer might have officially ended, but its effects can still be seen in the garden.
It has been a bit of a surprise to me to see so many well-established shrubs perish this year, killed by the sustained dry spell.
What has been even more surprising has been the plants that seem to have been more prone – many of them natives.
One of the first to show signs of stress in our neighbourhood was a mature Griselinia. These are native trees, often grown for hedging, but they make a great specimen tree in the garden, with bright glossy leaves. Their flowers are small and insignificant, as are the small fruits that follow – this is definitely one you grow for its foliage.
Its botanical name of Griselini littoralis indicates that the shrub should be able to cope with dry periods, as “littoralis” means “growing on the shore”. I would have thought that plants adapted to coastal positions could stand some dryness, but one of the neighbourhood’s trees has completely died.
Another coastal plant that has suffered this summer is the Wairarapa native, Brachiglottis greyii. This grows in rocky places along the Wairarapa shoreline, so it should be adapted to periods of drought. It also has silver leaves, usually a good indicator that it can cope with dry, sunny spots, but this year it has struggled, and I have noticed a few plants turning up their grey leaves and going to plant heaven.
Their large-leaved cousin, rangiora, seems to have fared even worse, as I have noticed some plants that have just folded their leaves up and given up the ghost.
Another type of plant that has not fared well has been the shrubby veronicas, known until recently as hebes.
Some varieties seem to have coped well, but others have died in abrupt fashion. Many of the garden hybrids are derived from V. speciosa, which again grows in coastal conditions, so you would think they would be able to cope with hot and dry weather, but it has not been the case this year.
I have also seen a few tarata and lemonwoods, that have struggled badly, but they seem to have mostly been able to recover. These are pittosporums, and their smaller-leaved cousins, the silver matipos, have struggled a bit as well, with a few dying off.
In a way, it seems contrary to the usual garden advice, to grow plants that are adapted to the conditions you are gardening in. Under those conditions, you would think that plants that occur naturally in or region would be the best to go for, but it may not always be the case. It is also possible, of course, that the plants are native to New Zealand but, in fact, come from quite different ecological circumstances. It would not be a shock if a plant that evolved to grow in Taranaki conditions didn’t do so well here.
It is something for gardeners to think about. What sort of gardens are we going to have in the future?
This year, we have struck an El Nino weather along with a warming climate. It seems that the temperature is going to continue to climb, and we are going to have to adapt our gardening style to the altered climate.
Perhaps we are going to be looking more at Mediterranean plants, and those from South Africa and Australia, plants that re already adapted for growing in warmer and drier climates. There is a problem with that however, t the winter was the coldest for a little while [El Nino effect again], so some gardens lost plants to frosts.
If the changing climate results in more frequent southerly storms, with their attendant sharper frosts, then it seems likely that simply changing to warmer climate plants will not work. This year our Pacific Coast Irises were hit badly by late spring frosts [they damage the flower buds] and then given another curry up by the dry summer.
For the next few years, I think it will pay to be very observant and to record what is doing well in the gardens around you. Take notice of those plants that are struggling with the climate and give them a wide berth – higher summer temperatures are bad enough, but they will also mean reduced flows in the rivers of the area, which in turn will mean that urban water supplies are going to struggle with demand.
Mulching and other soil conditioning tricks will help, but it looks as though we might need to slightly alter the palette of plants we use. Instead of bearded irises, we may need to use their cousins, the South African Dietes; we may have lavender in the garden instead of veronica, or rosemary or sage among the shrubs, and perhaps lamb’s ears and sedums will replace other perennial plants.
One way or another, we will always find a way to garden!
