Archive for the 'Frost Hardy Plants' Category

Eucalyptus forrestiana (Fuschia Gum)

Eucalyptus forrestiana (Fuschia Gum)

Eucalyptus forrestiana (Fuschia Gum)

Besides the local native mallee Eucalypt species, many Western Australian species have been planted around the district. These have proved to be hardy trees, frost and drought tolerant and very pretty in flower. One of my favourites is Eucalyptus forrestiana (Fuschia Gum).

This tree has attractive gum nuts (capsules) which have the appearance of a fuschia, hence the common name. It is often a tall shrub rather than tree like, being 3-7 metres high by 3-5 metres wide.

It seems to handle the limestone here very well although it is probably in the smaller range so far as size is concerned. It makes a great tree for home gardens. The Honeyeaters love this tree when it is in flower.

Eucalyptus socialis (Red Mallee)

Eucalyptus socialis  (Red Mallee)

Eucalyptus socialis (Red Mallee)

The Eucalypts are flowering prolifically this season. it always amazes me that the local Mallee Eucalypts flower and put on beautiful new growth during the hottest and dryest part of the year. The bees are very busy and the smell of honey is quite strong on a hot day.

I found this mallee at Lowan Conservation Park when we visited there a couple of months ago. It is a frost hardy and drought tolerant plant.

It is often cultivated because of its ability to grow on a range of sites in dry areas, including shallow limestone. It has a moderate growth rate and flowers at an early age. Its height ranges from 2 to 8 metres. Here it seems to be about 5 metres tall with a lovely wide canopy of foliage, making it a nice shade tree.

Chloris truncata (Windmill Grass) As Lawn

Chloris truncata

Chloris truncata

Chloris truncata (Windmill Grass) is a tufted perennial plant. Sometimes it behaves as an annual but I have proved it to be perennial if mown. Sometimes it spreads sideways by stolons in much the same way as couch grass but not so vigorous. It is wide spread in South Australia and also occurs in the Northern Territory, Queensland, New South Wales and Victoria.

It naturally occurs on sandy and clay soils including disturbed sites such as roadsides, and in grassy woodlands.

Information from the Nativel Grasses Resource Group says that the seed requires a lot of moisture to germinate. It has been seen sprouting while floating on the water in a sheep trough. An easy way to replicate this is to sow the seed in a pot and stand the pot in a container of water deep enough so that the surface of the pot remains very moist. Reduce the water level as the seed germinates.

We had about 3mm rain today. I don’t know how that will affect my experiment mentioned in the last post.

Chloris truncata (Windmill Grass)

Chloris truncata (Windmill Grass) watered and unwatered patches

Chloris truncata (Windmill Grass) watered and unwatered patches

I have a patch of Chloris truncata, a grass which is native to this area. Its common name is windmill grass because of the seed heads which form well above the leaves. A few weeks ago the poly hose on a nearby tap popped its connections and part of the chloris patch was watered. I was annoyed about it at the time but now I have more information about this grass. (The photo shows the plants that received the water next to the ones that would survive until the winter rains.)

This grass is one that is on a list of reccommended lawn substitutes, along with Austrodanthonia (Wallaby Grass), and Microlaena stipoides (Weeping Rice Grass). I was warned off the Microlaena because it really is a higher rainfall species, 500 – 700mm rain. As we are in a rain shadow, and a winter wet dry summer area (344mm rain per year), it was going to be a struggle to keep this looking reasonable without using more water than I wanted to. After all it is supposed to substitute for water hungry grasses.

Chloris truncata (Windmill Grass) Watered plant

Chloris truncata (Windmill Grass) Watered plant

The good thing that happened is that the Windmill Grass is green and has been for two and a half weeks. That is in spite of at least four days with temperatures above 41C and at least seven days around 36C. I will be letting it go and observing how long it takes to be unacceptable as a lawn. I don’t see much point in having a lawn if it can’t be kept green.

I was very pleased with the appearance of the plant. I had dismissed this species because my experience had shown it to be too tufted and therefore coarse to be a lawn. However the plant has spread and stayed low since it was mown about four weeks before the watering incident.

I am not sure how this will go so far as foot traffic is concerned. I will deliberately use part of it as a pathway to see how it copes with occasional walking. Unfortunately the patch is not near the house where I could walk on it constantly.

Some people have stated (and it is also in some articles) that Chloris behaves like an annual. We have not seen this characteristic because it is mown every year in late spring as part of our fire protection and to make it more pleasant to walk around our fruit trees. The mower is usually set at 3 out of a possible 6 settings. The mower is driven around on the 6 setting. 3 is a bit low for the spear grasses but for the Chloris it seems to be ideal. The patch seems to increase in size and thicken every year.

I am not sure what to do now. I think I will dig a few clumps and divide them and grow them on in forestry tubes to be planted out with the late autumn rains next year. I will also at that time try dividing and planting dirsctly into the ground. In fact that is a possibility now. (Too many other things to do.)

Preventing Frost Damage In Australian Native Plants

I was reading some past copies of Journals from interstate groups of the Australian Plants Societies. I came across an article by Rodger Elliott in ‘Native Plants for New South Wales’. It was titled ‘Can we prevent frost damage?’ According to Rodger there are a number of strategies we can use to minimise the damage like many of our plants suffered last winter. Plants which are labelled as being frost hardy have the proviso added ‘in years of normal rainfall’. So in times of drought the likelihood of frost damage is increased. Now is a good time to take stock and perhaps move plants which may be at risk of damage and plan other precautions for next Autumn.

Frost damage can occur in some plants at about 1-2 degrees C, in others at about -4 degrees C and more at -8 degrees C.

Some Ways To Minimise Frost Damage

  • Only cultivate frost tolerant plants.
  • Look for areas where frost does not occur and use these places to grow frost tender plants.
  • Do not apply nitrogenous fertilisers after mid summer in frost prone areas.
  • Frost damage occurs when cold air is unable to flow away from an area. Make sure weeds are removed and mulches are flattened rather than heaped around plants. Hedges can prevent the free flow of air.
  • Keep soils moist.
  • Gravel and screenings are better mulches in frost prone areas.
  • Do not prune in winter or spring until frosts have finished for the season.
  • Hessian is a good cover to provide overhead protection. Do not use plastic.
  • It has been shown that seaweed sprays strengthen plant cell walls and therefore have a beneficial effect in protecting plants from some frost damage. These are also thought to assist plants to withstand excessive heat.