AUTUMN days are a great delight in the Australian National Botanic Gardens.

Visitors will see two particular plants that they might have growing in their own gardens – Dicksonia antarctica or tree fern and Xanthorrhoea or grass tree.

Starting with tree ferns – 80 per cent die in a short time from poor siting and watering requirements.

All tree ferns sold are taken from the bush under strict licensing regulations by the Parks and Wildlife Service and must have a serial-numbered tag to prove they were not removed illegally.

Always select a good healthy plant free from physical or insect damage from a registered garden centre with the tag attached. When siting your tree fern, ensure it has ample shade.

They originate in shady forest areas where they get neither direct hot sun, blasting hot winds or severe frost settling on the fronds. This can be under trees or shade cloth. In heavy soils, dig deeply adding plenty of organic matter such as rotted leaves, cow manure and coarse river sand.

Good drainage is vital. Place a third of the trunk in the ground and immediately thoroughly water in with Maxicrop Seaweed Plant Nutrient to encourage strong root growth.

Tree ferns should be watered in the crown of the fern and around the base. If drip irrigation is used, make a circle around the base and a line to the crown.

Mulch well, and if you have no accumulations of rotted leaves etcetera, Canberra Sand and Gravel’s Organic Mulch is ideal. In the forests, they have plenty of rotting natural leaf litter.

In summer, a good, deep soaking once a week is usually sufficient. An application of seaweed solution several times in spring and summer is sufficient as most of their nutrients will come from the mulch.

The only real pest for tree ferns is scale insects on the back of the fronds, usually indicated by a lack of vigour and health in the fronds. Ants often accompany the scale and these do no damage, actually attacking the scale insects. Multicrop EcoPest will fix scale, mites and other sucking insects by spraying it on the underside of the fronds.

Xanthorrhoea are a truly ancient tree and can live for hundreds of years. As with tree ferns, their removal from the bush is strictly prohibited except by licensed companies.

Normally these are dug and held in a specialist wholesale nursery for 12 months until they display new growth and roots before being offered for sale.

Preparation of the hole is the same as tree ferns. It is preferable to cut the pot away from the plant rather than risking damage to the roots by banging the pot off the plant.

Grass trees have a fairly shallow root system with most feeder roots within the top 60-70cm of soil. When planting, water in the same as tree ferns with plant nutrient.

Its distinctive flower spikes usually appear when the tree is well established and over a metre tall.

Patience is the name of the game with grass trees and they take their own time to flower.

Extra watering or feeding will not hasten their growth and flowering. Once established (and they can grow to two metres in a couple of months), they usually produce flower spikes each year. Whereas the trunk will normally only grow about 10cm a year.

A tree two metres tall could easily be more than 200 years old. The one in the picture is possibly at least 300 years old. Your grand, great and great great grandchildren will enjoy the ones you plant today.

THE Great Autumn Plant Sale by The Growing Friends of the ANBG will be held from 8.30am to 11am, Saturday April 13.

Plants, priced at $3 and $5, have been propagated by the Friends from material in the gardens. The plant list is available on anbg.gov.au/friends. Bring boxes, bags or even a trailer for your purchases.

THANK you to those who sent emails regarding the proposed chopping down of the stand of poplar trees at Braidwood. I have forwarded your comments (less names and addresses) to the mayor of Palerang Shire, which includes Braidwood. Keep them coming to cedricbryant@grapevine.com.au