Propped Up Wet and Wild

Propped Up: Wet and Wild

Newsletters, The Scoop

By now you should have had a chance to look around your yard and find a spot for maximum winter sunshine and good access (with any luck there will have been a sunny day or two in the past month) and thought about potting up and growing benches. This month we’ll be having a look at watering systems but before that a quick chat on nursery hygiene. 

I mentioned last month about having a quarantine area to keep plants you’ve brought in away from plants you’re propagating as a way of minimising weeds and diseases it’s also good practice to wash and dry your pots, and I really should practice what I preach here (washing in bleach is ideal but getting any old potting mix off is the main aim). Probably of even more importance is not reusing potting mix, there’s a big temptation to reuse it but the risk of introducing weeds or diseases into newly potted stock makes it just not worthwhile.


Rough but reliable! Our current timer set up.


Half circle microjet sprays on 30cm risers

The good news is most weeds and diseases which thrive in nursery conditions don’t do well in gardens so old mix is generally fine to go into a hot compost or as garden mulch.

Probably the biggest cause of failures in nurseries is water, either too little or in probably most cases, too much and watering systems need constant readjustment to take into account differing weather conditions and different growth stages of plants.

The best watering system is a knowledgeable and observant person with a watering can, which works well with a small nursery and someone there full time unfortunately unless we’re lucky enough to have someone there full time we need to think about some sort of automated watering system.

Every nursery has different needs and these will change as your plants grow, in short, small plants need a little water, large plants need a lot, the following is what works for me and why.

Timers: I use the cheapies (about $30 each), single outlet, 2 dials on the front , run by a 9 volt battery, I’ve found them to be robust, reliable and able to handle high water pressure, the big downside is their limited adjustability which means seedling trays often get too much water (you can compensate a little by improving the drainage of your potting mix – more on that next month). The more expensive units are great for adjustability however at the current site the high water pressure kills them pretty quick. 

Currently the irrigation is set at 2 minutes every 24 hours across the nursery, which is a bit high for some and a bit low for others.

For the irrigation itself I use 40 litre/hour half circle microjet sprays set about every 50cm arranged around the outside of my benches. Facing inwards means the water goes mostly over the benches and you’re less likely to get wet if you’re caught in there when the water starts.

The microjets are on 30cm risers which can get in the way when moving trays around but there’s less overspray and less dripping than would occur from overhead sprays. 

Every now and then if I have a lot of plants in I’ll add in a square spraying lawn sprinkler,these do use a lot of water so it’s not used often.

There’s been a lot of trial and error and there’s always adjustments needed depending on life stage of the plants and prevailing weather.

Next month: Soils aint Soils.


A square lawn sprinkler, simple and effective, not terribly efficient.