From Jon Lamb Communications
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January 11, 2019

Heat damage widespread

Heat stressed vegetables and plants with severe leaf burn were a common sight following the Christmas – New Year heatwave.
Leaf burn was certainly more widespread than expected, with plants in many gardens simply running out of soil moisture.
Unfortunately some gardeners also lost favourite container-grown plants.

Running on empty?

Keen gardeners who like to check the soil before they re-water were surprised at how quickly the topsoil dried out, both from containers and garden beds.
This is not surprising. When temperatures run into the very high 30s and beyond, plants with a healthy root system use every drop of moisture just to keep cool.  
With more extreme heat on the way a systematic soaking of the garden tonight or possibly early tomorrow morning is highly recommended.
It’s worth repeating – plants with healthy roots that are well watered before the heat sets in will suffer little if any damage.

Too much of a good thing

Ironically, heatwave feedback from a number of gardeners indicates the main reason for container plant collapse during the heat was over-watering.  
In this situation the air spaces between the potting mix particles were continually filled with moisture. Without air the plants drowned.
Checking the top 1 to 2 cm of potting mix is completely dry before re-watering is a useful guide.

Weather to remain warmer and drier

Warmer and drier than normal weather is likely to continue through late summer and extend into early autumn, with best prospects for significant rain not occurring until early February.
This was the three-month weather outlook for SA gardeners presented by Bureau of Meteorology climatologist Darren Ray on ABC Talkback Gardening last Saturday.
Darren believes Adelaide’s summer heat will continue to arrive in short spells rather than extended waves.

Summer fruit harvest underway

SA’s summer fruit harvest is now well underway. While crop yields generally are good, fruit size in many gardens is reported to be smaller than normal.
More on the link between fruit size and watering in my Advertiser gardening column tomorrow.

Watering fruit trees

Fruit trees have their main moisture gathering roots well below the surface at 15-35cm. 
This is the area that needs to be soaked when you water. 
Light surface watering with a handheld spray is usually ineffective, as most of the moisture is lost through evaporation.

Watering Guide

A mature fruit tree (3-4m x 3m) carrying a heavy crop will need around 200 litres of water a week as the fruit approaches maturity.
However, this should be increased to 500 litres per week during the two weeks before harvest.
While this sounds like a large volume of water, keep in mind a standard hole-in-the-centre sprinkler that is often allowed to run for 30 minutes and more will distribute 200 to 300 litres of water in 10 minutes.

Controlled-release boost for fruit harvest

Summer is a bountiful time in the home orchard, so whether you’re growing a whole
fruit forest or just a few trees in pots, now is a great time to give them a boost.
If you want bumper crops with enough to share around, then give your fruit trees
 a good dose of PowerFeed Controlled Release Plant Food for Flowers, Fruit & Citrus.
This Powerfeed contains all the right nutrients to promote healthy growth as well as an
abundance of flowers and fruit.
It is also boosted with seaweed to stimulate strong healthy roots and reduce stress on
plants AND it is packed full of beneficial microbes.
Many fruit trees will also benefit from a summer prune after the crop is harvested.
Remove any dead or diseased wood as well as crossing branches to promote a super
crop next year.
Irrigation Guide

Watering with a micro irrigation system

Micro Irrigation can be defined as a watering system that:
  • Applies water at a low rate.
  • Applies water over a long period of time.
  • Water is applied at frequent intervals.
  • Water is placed near or into the plant’s root zone.
  • Applies water via a low-pressure delivery system.
If we consider these points to operate a micro irrigation system correctly, we need to ensure that we allocate adequate run times (how long) and frequencies (how often) between watering.
We need to monitor plants for signs of water stress (drooping leaves or leaf burn) and adjust our watering schedules to suit the conditions.
This is particularly important in the peak of summer when the onset of plant stress can be rapid.

How long to water (run times)

Typically, it is not uncommon for low flow fixed drippers i.e. 4 lph to have run times of 1 to 2 hours daily in the peak of summer, whereas adjustable multi outlet drippers (Shrubbler®) or Sprays can typically run for 15 to 30 minutes daily.

How often to water (frequency)

The frequency of irrigation is determined by the current weather i.e. in spring you may water every 2nd or 3rd day versus in the peak of summer watering twice per day (morning and early evening).
Watering with a micro irrigation system is not an exact science as there are many variables that can affect watering efficiency and these need to be considered and the schedules adjusted accordingly.
We have put together a basic watering guide for Adelaide to assist you in your watering decisions.

Download the micro irrigation watering guide here »

Send us your diary dates

Don't forget to send us your garden event dates and details for inclusion in the Good Gardening "What's On" calendar.
You can email us here »

Don’t neglect camellias

Camellia bushes are often neglected at this time of the year as they are not flowering or producing vigorous growth.
However, they are busy producing new flower buds for their winter and spring displays.
Plants in containers should be soaked, incorporating an application of a soil wetting solution and a quality seaweed product.
Lawn Care – Stefan Palm

Lawns – good value for money

How much would you pay for an average front garden lawn?
While it’s hard to put a realistic value on the look of a lawn, if you paused for a few minutes and started to think about the many benefits linked to the lawn, you may be surprised.
In this week’s lawn blog, SA lawn advisor Stefan Palm considers the many benefits of growing a lawn and why collectively they are an important part of our urban landscape.
More information »
Paul Munns Instant Lawn

How to improve pollination prospects

Cantaloupes, melons and pumpkins produce both male and female flowers on the same plant.
Initially there are more male than female flowers (to attract more bees). 
As the season progresses, you can increase the number of female flowers by removing the tip growth of the longest runners. 
This is particularly effective for pumpkins. 
Insects are the main pollinators particularly bees.  Most pollination is carried out relatively early in the morning.

Orchids need cooling

During summer, cymbidium orchids are moving through a critical stage of flower initiation for the following season.
Your chance of increasing the number of flower spikes later in the year can be boosted considerably if you can create a night time drop in temperature around your plants of 10°C.
This can be achieved by misting or showering your plants for a few minutes with water late in the afternoon or during early evening, particularly when conditions are very warm.

Indoor plants need good light

Spindly growth on indoor plants usually indicates  inadequate light. If possible, relocate the plants where the light is bright, but don’t place them in direct sunlight or the leaves will burn.
Remember to rotate indoor plants on a regular basis so that all parts of the plants are turned towards the light.

Please keep your questions for Talkback Gardening

Good Gardening  is unable to answer individual reader's questions via email.
If you're looking for specific gardening advice please give me a call on ABC Radio Adelaide's Saturday morning Talkback Gardening  or speak to the experts at your local garden centre.

Open GardensOpen Gardens

Saturday, January 12 and Sunday, January 13
7 Golding Road, Stirling
A formal English-style garden in keeping with the traditional architecture of the house. Beautifully crafted stone walls and clipped hedges form strong bones for the garden, which is divided into distinct garden rooms, each with its own theme and colour scheme.
More information on the garden and directions »

Gardens open 10 am to 4.30 pm.
Entry $8 - OGSA members; $6 - Government concession card holders; children under 18 free.

More information on the 2019 season »

Weekend gardening weather

Talkback Gardening tomorrow

ABC Radio Adelaide Talkback Gardening this Saturday – phone me and Deb Tribe on 1300 222 891 and have your own gardening question answered.

Topic – The big benefits of using temporary shade in the garden.
Guest – Dominic Cavallaro, vegetable agronomist for Ag & Seed, Virginia.

Coming soon

Saturday, April 6 and Sunday, April 7, 2019
Enfield Horticultural Society’s Autumn Show
Saturday 12 noon - 5 pm, and Sunday 10 am - 4pm, Klemzig Community Hall, 242 North East Road, Klemzig. Admission $2. Enquiries 8251 2299.

Regular garden attractions

Adelaide Botanic Gardens – free guided walks
Friends of the Botanic Gardens of Adelaide guided walks for the public at Adelaide, Mount Lofty and Wittunga Botanic Gardens, and Botanic Park.
More information »

The Waite Arboretum, Fullarton Road, Urrbrae

Open free to the public every day of the year from dawn to dusk, except on fire ban days. Free guided walks on the first Sunday of every month, 11 am to 12.30 pm.
Meet at the West lawn (Croquet Lawn) of Urrbrae House. Bookings not necessary.
More information »

Urrbrae House historic precinct gardens
At the end of Walter Young Avenue, off Fullarton Road, Urrbrae, or from the Urrbrae House gate, Claremont Avenue, Netherby.
Open from dawn until dusk every day. Free entry.
More information »


Disclaimer: Although all reasonable care is taken in preparing information contained in this email, neither Jon Lamb Communications (JLC) nor its officers, staff or suppliers involved in the editing and production of this email accept any liability resulting from the interpretation or use of the information set out in this document. Information contained in this document is subject to change without notice and is of a general nature and should not take the place of professional personal advice. No responsibility is accepted by Jon Lamb Communications for the accuracy of information contained in web sites linked from this email. Publication of an advertisement does not constitute endorsement by JLC of any product or service, or warrant its suitability.

Copyright © 2019 Jon Lamb Communications, All rights reserved.

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