Garden guide by Newcastle gardener, Brian Holt

Newcastle Garden Guide by Brian Holt For May – June


On most days, May is warm and balmy in the daytime and fresh in the evenings. Those stinking hot, humid days are a distant memory. Days are shorter, which unfortunately means that there is less time available to garden and things will grow a bit slower. This can mean that gardens and pots don’t get watered and weeded by busy people, so you need to use whatever means you have to ensure things are done, or otherwise things can get ugly. Monitor the need for watering, as soils will retain moisture for longer. Turn off automatic watering if it’s not needed. Keep an eye out for bugs, slugs, snails and other pests, such as mealy bug on many plants. Be prepared to squash unwanted snails and caterpillars or else resort to snail pellets for snails/slugs and Dipel for caterpillars. There is a more child/pet/lizard friendly version of snail pellets available. The key is eternal vigilance and a daily walk through the garden. Ignore it at your peril.
Make use of Saturaid, or some form of wetting agent, to keep pots evenly moist but not too wet. Always monitor your mulch levels and be prepared to top up where needed. If you’ve been lightly pruning roses after flowering, you will be enjoying a succession of late flushes, especially from the abundant flowering Iceberg varieties. If you planted your pansies a bit too early, then you may need to top them up with some more. In any case, grow some extras in pots as spares.
Look out for onion weed at this time of year. Don’t cultivate the soil where it is present or you may become an onion weed farmer. Unless you are confident in doing so, don’t attempt to dig them out. Instead spray carefully with glyphosate, except avoid over spraying onto most plants, or they may die also.
You can still plant spring bulbs in May in our climate. Make sure you follow a guide for their depth and always have them pointing the right way up.
Plant Citrus now into rich and very well drained rich soil. If you don’t get that part right, forget about them ever doing well. Camellias are also a good idea. You can see them in flower and select a good looking variety. But make sure you look at how big they grow and select a variety suitable for the sun exposure you expect. Camellias grow really well in good sized pots and the size they grow in the ground won’t matter, as they seem to adapt to the pot size. Keep potted Camellias moist but not saturated so they don’t drop their flowers, Cyclamens will be coming into their own as the weather cools. Back in the day when milk came in bottles, you put the empties out for the ‘Milko’ at night. Cyclamens should also be put out at night, so they can benefit from the cold. A good job for those with deciduous trees is to gather the leaves and make use of these as mulch or as a compost material, or by piling them up in a heap of their own and adding manure (or organic fertiliser) and moisture to speed things up. Then wait a very long time and the resulting compost will be a great soil conditioner. Running over them with the mower will also speed up their decomposition.
Top up rose gardens with a dressing of cow manure & a layer of sugarcane mulch. Roses love this and according to a mate of mine who worked in the Botanic gardens, this is almost essential for them. Be careful to not overuse cow manure in some gardens as it can make things too moist for some plants. My favourite option for mulch these days has various names at landscape suppliers. It’s aged tree lopper’s mulch but can be called Forest mulch, leaf mulch or any other name that suppliers come up with. It works because it has larger pieces mixed in with a lot of fine material that breaks down into humus. So it retains moisture and suppresses weeds really well, while actually building up organic matter in the soil.
In warm sunny spots, Storm/Autumn/Summer Crocus are a great addition to complement annuals, with their bright white flowers. They are grown from rapidly multiplying bulbs, which can be spread around and may need thinning out if they do too well. Long lasting Dianthus also adds to the colour of annuals and fills the void while you are waiting.
Other things to consider planting in May are Tulips, Azaleas, Conifers and Roses. In the veggie patch plant broad beans, Kale, onions, shallots, peas and cabbage. Keep up plantings of Coriander in warm spots with rich soil.For more info on things to plant now visit



About now, looking at your front nature strip, you may begin to wonder if the postman’s motorbike is what started the Grand Canyon.
You can plant a lot of different plants at the moment and know they will not be blasted to death by the sun. I like to take cuttings of different things now, such as Vinca, Geraniums and Fuchsias and just shove them in pots or straight into the garden. If they grow it’s a bonus.
Sunshine on my shoulders makes me happy, sang John Denver. I’m sure he meant winter sun in our climate. Get out in the garden and enjoy it when it’s there. Keep the mower up high while lawns are slowing down.
Raking autumn leaves is a chore which could actually be enjoyable at the moment. Soils will be cooling down as daylight is less. Beware of watering to the point of saturation, especially late in the day, or else plants may be given a freezing cold bath. Keep mulch levels up; right now it will help retain soil warmth. Winter time is also renovation time. You can take advantage of plant dormancy to move things around and make changes to your gardens if needed. If you want to you can divide older clumping herbaceous perennials (plants that die down in winter and re-emerge in spring each year), after lifting them, so that you can use them in other parts of the garden, or give some away. Summer flowering shrubs can be pruned now, but only as much as is needed. I like to prune some Grevilleas in the cool weather, as they won’t die back like they could in hot weather. This will keep them from growing long and rangy. Don’t fertilise now, as plants will not take up nutrients. However, if you spread a bit of well formed compost around plants and veggies prior to mulching, it will encourage worms and condition the soil. A little cow manure is also good as it is mild and good for soil.
In the garden plant tuberous begonias, cannas, gerbera, iris, sparaxis and bare rooted roses. And if you want to remind yourself of Grandma, wack in some gladioli. A great source for many of these plant options is the mail order supplier, Tesselaar.

In the food gardens, plant strawberries, silver beet, Kale and rhubarb. But you will be pushing your luck with many herbs, such as Basil and Coriander, so don’t bother with these unless you have a glasshouse. For more info on things to plant now visit
your lawns for Bindii and clover. If your lawn was mown too low in summer, you will have a lot. You can start spraying them if you think you need to. If you wait till spring, they will have already sprung! Ask at your nursery for the appropriate stuff. Just remember, Buffalo lawns resent Dicamba based products. If you have couch or kikuyu, I would use Yates Weed and Feed. But do follow directions and watch for over spraying the garden. Personally, I don’t use it on my own lawns, particularly on my back lawn which is close to my vegetable patch. I just mow more frequently and hand remove any Bindii. Clover retreats again in summer.