The magic of mulch

Sunny, hot weather usually cues us that we need to get out and top up the mulch in our garden beds. But there are other reasons why your should mulch (or top up your exisiting mulch layer) at the start of summer. Here’s a few other benefits that mulching will bring:

• Regulate soil temperatures - Mulch helps to regulate soil temperatures and supports plants that are coping with extreme weather. A mulch layer reduces heat absorption and will be cooler than soil directly exposed to sun.

• Prevent moisture loss. Moisture loss occurs when the sun causes evaporation. But windy weather can also dry out the soil and stress your plants.  

• Help prevent spread of disease. Mulch provides a physical barrier that protects against soil borne diseases. For example, mulching under roses can help stop black spot fungal spores in the soil from being splashed onto the leaves during a rain event.

• Suppression of weeds. A mulch layer will block light and therefore prevent many seeds from germinating.

• Improves soil. Some mulches such as pea straw are high in nitrogen and as it breaks down this nitrogen returns to the soil increasing nutrient content available to plants.

• Protects from soil erosion. Without a layer of mulch covering the soil, top soil can run off your garden beds during heavy rain events.

• Increased production. Studies have shown that plants grown in mulched beds grow faster, contain more chlorophyll, and greater root growth. If you are growing fruit and vegetables, you will harvest more food from a crop that has been mulched.

• Indirectly, mulch can help reduce insect activity. By helping plants to improve their overall health, they become less susceptible to insect attack.

Types of mulch

There are many different materials you can use for mulch and you will find something suitable for every garden. 

• Straw mulches (Pea Straw, Lucerne Hay, Sugar Cane) - great for the veggie patch, they can be bought in compacted bales. The hollow centres of the straw also has an insulating effect. Pea straw contains nitrogen that will break down into your soil, improving the overall condition.

• Bark mulch - inexpensive and lightweight, bark mulches are easily spread over the garden. Larger chunks of bark will take longer to break down, but may blow away in windy weather. Bark mulch is not the best choice if using it in the vegetable garden, as it can pull nitrogen away from the plants.

• Stones/rocks/gravel - gravel mulches are great for their water holding capacity, and also providing warmth to soil. In winter this can help support plants that don’t like cold.

• Lawn cuttings. You can use dried grass clippings on your ornamental garden or veggie patch. This will break down and provide a good source of nitrogen. Just don’t use cuttings that have invasive weeds or if you have sprayed your lawn with herbicides.

• Leaf litter from deciduous trees - if you have a deciduous tree, you have free mulch! In autumn, throw your leaves onto the soil and it will break down into a beautiful soil conditioner. Why waste such an amazing natural resource!

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Gravel mulch

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bark mulch

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straw mulch

Some tips for mulching your garden

• A good guide to how much mulch is to apply around 5-10 cm layer of mulch

• Make sure the soil is damp when the mulch is applied, and then water the mulch once you have laid it out

•  Avoid letting the mulch touch the stems of plants, as it can cause the plant to rot

• If the mulch becomes water repellent, soil wetting agents can be applied to rehydrate it

• When mulching trees, make sure you go right out to the canopy line to make sure you are protecting any shallow roots
  

Summer watering

Watering is important to keep your garden healthy and resilient during the heat of summer. But it's not always straight forward, and sometimes we end up accidentally killing our plants by watering too much or not enough. Here's a few tips on how to water your garden in summer.

• Watering deeply every few days is usually better than watering every day. A deep watering will encourage roots to dive down to seek out the water and will build larger, healthier root systems that will help them survive when it’s dry. (A veggie garden that is actively producing food will most likely need daily watering).

• Pots need to be watered daily, and possibly more than once a day if it’s very hot and windy. Terracotta pots will dry out a lot faster than plastic pots.

• Don’t water in the middle of the day – you will lose water to evaporation. It is much better to water in the morning or in the early evening.

• Note that if you water in the evening, plants that are still wet when the sun goes down can be susceptible to fungal diseases so try not to water the leaves if watering in the evening - aim the water at the soil and avoid the foliage.

• Better still, have an irrigation system installed that can deliver water slowly and efficiently to the plant root zone without you having to remember to do it.

• Trees need to be watered right out to the drip line of the canopy rather than just at the base of the trunk.

• Succulents need water too! Water deeply once a week in the morning if the soil is dry (make sure they are draining freely). If the soil feels moist then wait a couple of days.

• Watch the soil surface when you are watering. If the water seems to pool on top and doesn’t absorb, scratch the top of the soil. If it’s dry under the top layer, your soil is hydrophobic and your plants are not getting any water in their root zone. Wetting agents can help with rehydrating the soil.

• Newer plants will need more water than established plants while their roots are establishing.

• While native plants and drought tolerant plants can survive dry periods much longer, they still need to be watered, particularly young plants that are trying to establish themselves.

• Mulch on the garden beds will help the soil stay moist for longer.

• Finally, don't forget to leave some water out for wildlife. Your neighbourhood birds, reptiles and bees will appreciate it!

Choosing plants for your poolside

Being a poolside plant would have to be up there as the hardest gig in the plant world. Poolside plants are splashed with chemicals, exposed to sun, sometimes inundated with water and jumped on! So when you are choosing plants for your poolside, you should choose the toughest and hardiest – as only the strongest will survive.

You also need to consider the plants physical characteristics. Are they spiky? If so, they probably aren’t great where kids will be playing. Do they attract bees? Perhaps you don’t want them foraging where people will be walking barefoot. Do they drop leaves and/or petals? This could be very annoying for the person responsible for cleaning the pool. Does it have strong root system? This could cause problems for the structural aspects of your pool.

No plants will love being constantly barraged with chemicals, but some cope better than others. Here’s a list of top pick plants that we think you should consider for your pool area.

Ground covers

Trachelospermum asiaticum (Japanese Star Jasmine)
Dichondra ‘Silver Falls’

Shrubs

Geraniums/Pelargoniums
Hebe sp
Westringia fruticosa (Coastal Rosemary)
Rhaphiolepis indica (Indian Hawthorn)
Nandina domestica (Nandina)

 Trees

Magnolia ‘Little Gem’
Banksias
Olea europaea Olive

Grasses and strappy leaves

Agapanthus orientalis (Agapanthus/African Lily)
Strelitzia reginae (Bird of Paradise)
Anigozanthus flavida (Kangaroo Paw)
Calamagrostis x acutiflora ‘Karl Forester’
Miscanthus sinensis
Lomandra longifolia
Carex sp
Festuca Glauca (Blue Fescue)
Penesetum rubrum (Purple Fountain Grass)
Ophiopogon japonicus Mondo Grass
Dietes iridioides (African iris)
Cordyline australis
Liriope muscari (Lilyturf)

 
Succulents

Agave attenuata
Succulents such as Aloe sp, Echeveria sp, Sedum serpens ‘Chalk Sticks’, Cassula ovata)

Palms

Dypsis lutescens (Golden Cane)
Howea forsteriana (Kentia Palm)
Rhapis excelsa (Rhapis Palm)

 
Climbers

Trachelospermum jasminoides (Chinese Star Jasmine)
Bougainvillea glabra

A word of caution - bamboo gives a lovely tropical feel around a pool, but think twice before planting and seek advice before choosing a variety. Bamboo can be invasive and will be very difficult to remove later. If you really want to plant bamboo, choose a non-invasive variety like Bambusa textilis ‘Gracilis’ which is a fast growing, clumping variety.

Helping your garden survive summer

You may have noticed the government running ads promoting the Target 155L water saving campaign. While we are not officially in water restriction stages, it's an indication that may be where things are heading, and if it does the first thing to suffer is our gardens. 

Some gardens fare better than others in the heat, and this all comes down to plant choice, along with some  key gardening practices. 

Choose plants that have lower water requirements

• In general, Australian natives are a good choice as they are used to much less rainfall than exotic plants. Lilly pilly, kangaroo paws, crowea, correa, coastal rosemary, native grasses, eremophila and native daisies not only fit in beautifully with other species, they provide a valuable food sources for native birds and beneficial insects.

• Plants with grey tones.  It is safe to say that if a plant is grey and furry it's fairly certain it has evolved to live in dry conditions. Plants like lavenders, euphorbias, convolvulus, helichrysum and lambs ears have grey leaves that reflect light away from them, helping them withstand the hot summer sun a lot better than others.

• Plants with leathery leaves are another indication of toughness! Magnolia Little Gem, Bay Laurel, Rhapiolepis indica are just a few examples. Just take a drive along the coast and you’ll see them growing happily.

• Plants that thrive in Mediterranean climates also grow well here in Melbourne, so if you have just been to Greece and feel inspired then you are in luck! Think of the herbs used in Mediterranean cooking - rosemary, sage, oregano, thyme.  Not to mention olives!  All of these thrive in hot weather and don't need much water. 

• Succulents seem to be finding their niche as our climate changes. They thrive in coastal gardens and are happy with very low watering so these plants will continue to grow in popularity as more of us discover their true value in the garden.

Supporting your plants through summer

There are a number of things you can do to give your plants a better chance of making it through summer.

• If you only do one thing, then let it be mulch!  A good layer of mulch helps insulate the plant roots from the worst extremes of the weather, and also helps the soil retain water so it doesn't dry out as fast.

• Watering in the morning or evening directly on the soil rather than the foliage is a more efficient use of water as it's going straight to where the plant needs it. There's also less risk of evaporation. If you have a drip irrigation system, do periodic checks to make sure the nozzles are not blocked.

• There is evidence that using Seasol on your plants can increase their resilience to summer heat, and helps keep your plants healthier, so a regular application can be a big boost for your garden.

• If you have plants with burnt foliage, don't be tempted to cut it back right now.  This will only encourage the plant to put on tender new leaves which will be exposed to the hottest summer sun and will likely burn them as well.  Wait until the milder days of autumn before cleaning up any damaged leaves.

• Dust storms can make the garden look a real mess! While the dust can actually benefit the plants with the addition of micronutrients and minerals such as iron, it can impact on the plant’s ability to photosynthesise. Washing excess dust off the leaves will help.

Life is too busy for us to spend too much time nurturing plants that aren’t really suited to Melbourne’s weather. Replacing stressed out and struggling plants with hardier ones will make your life easier in the long run, and will be so much more rewarding!

Her'e’s a pick of a few of our favourite drought tolerant plants.