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Wellington Gardens Blog


Summer in the garden

Dec 1

Written by:
Thursday, December 1, 2016  RssIcon

It may seem ironical to be discussing what to do with wet areas as it is now officially summer! However we have had some very wet weather two weeks ago that exposed a lot of drainage issues. We need to be able to accommodate for  extreme weather conditions ( as well as earthquakes!).

I have talked to a number of people recently who have had problems with excess water and drainage.  There are a number of situations that will cause these problems:

1.            If your house and garden are at the bottom of hill, you will get runoff from higher areas. If the water can’t move away fast enough you will get a build up.

2.            If you are living on the flat near a river it can back up and overflow onto your garden.   

One situation that increases water runoff is hard surfaces. Every time a new housing development takes place you will usually get an increased area of hard surfaces, such as tarseal, paving or concrete. These surfaces pick up water and hopefully quickly direct it to the nearest storm water drain. The extra water puts pressure on the storm water system, or can run off onto neighbouring properties. A lawn area or garden is absorbent, thus reducing the likelihood of runoff.

What steps can you take to reduce flooding or ponding on your property?

1.            Install drains at points to intercept water before it creates a problem. For example, you can install a Novaflo drain (those black plastic flexible pipes) at the bottom of a trench and backfill with drainage metal. Ideally place the drain at a point where it will intercept water runoff, and then you can connect the Novaflo with existing drains or into a waterway. You should always have a Novaflo drain in behind a retaining wall to divert water.  

2.            Make sure all surfaces drain away from your house towards a stormwater drain. You can use channel drains or sumps with grills connected to a stormwater to divert water.  

3.            Create gardens and lawns to absorb excess rainwater, but make sure there is a gentle slope on the lawns so the water can also drain away.

4.            If you have a wet area that is difficult to drain excess water away, you could turn it into a bog garden or water feature.   

If your garden is likely to be inundated for more than 12 hours at a time, you can grow bog or water plants. Some plants have adapted to growing in these conditions, which can kill many plants such as rhododendrons. Note, if your plants that prefer free draining conditions get vey wet, and then very dry, the stress on the roots can cause them to grow poorly or die.

Here are some plants you can use in permanently wet conditions:


Astilbe, false spiraea

Iris kaempferi

Ligularia reniformis, tractor seat plant

Lobelia cardinalis

Primula. bog primula

Shrubs and trees

Cordyline australis, cabbage tree

Leptospermum sp, manuka

Nyssa sylvatica, tulepo tree

Rhopalstylis sapida, nikau

If you are prone to flooding you may as well grow plants that suit the conditions. If you live near a stream or river it is advisable to allow for flooding.

The alternative to using these water tolerant plants is to use a raised garden. This is especially useful when you want to grow vegetables, as you can backfill the garden with a well drained fertile mix such as compost and good quality soil.

If you need help with a wet area then let me know.




     Cabbage tree



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Recent Blog Entries

How to have a great lawn
How to grow edible plants in your garden
Winter in the garden
What to do with steep banks
Spring in the garden
What to do in the garden now its winter
Autumn ( or late summer) in the garden with succulents
Summer in the garden
Spring in the garden
Paths & driveways
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