Determining which watering system to use

The amount of water your garden needs depends on what kind of soil you’re using, what your climate is like, and what kinds of plants you have. Shallow rooted plants, for example, need more water than deep-rooted ones for the simple reason that they’re closer to the soil surface, which dries out more quickly in the heat of the sun. Deep roots can reach the more consistently damp lower soil layers.
For many gardeners, getting enough water to their gardens is the biggest gardening challenge. If you’re crunched for time or have a large area to water, installing in-ground sprinklers and irrigation systems may be a good idea. Employing the use of a regular watering system, such as drip irrigation or an in-ground system, is the best approach to ensuring a consistent moisture cycle to grow happy, healthy plants. However, in-ground watering systems tend to be expensive and should be installed by professionals. If you’re looking for suppliers of irrigation systems, the companies in the Appendix may be a good starting point.
Of course, you can always water your garden yourself, by hand, and really that’s a great way to do it, because you can personally inspect each plant. Whether you water by hand or use a system, here are some things you may want to keep in mind:

• Watering your garden early in the morning, before the sun is fully overhead, is usually best. Watering at night can make plants susceptible to diseases that cause them to rot.
• Some plants in your garden, such as melons, may require more water than others, in which case watering by hand is probably best. _ If you don’t have an outdoor spigot close to your garden for convenient hose hookup and watering, a rain barrel may be a good substitute for keeping water close to your garden. Various mail-order suppliers sell rain barrels.
• Make sure you get a barrel that’s tall enough so pets can’t get in, or put on covers to reduce drowning risks to pets and children. To keep mosquitoes out, use products like Mosquito Dunks, which are donuts of a type of bacteria that’s harmless to humans but deadly to mosquito larvae.
• Usually, watering the soil rather than the leaves is best because the roots are what absorb water, and they’re in the soil. Also, wetting the leaves can result in more disease problems. Still, on a very hot or windy day, watering the leaves can reduce wilt and lower leaf temperatures.
  
• Unless you have a very large garden, sprinkler heads that you attach to garden hoses are usually better suited for lawns than gardens. If you decide to use one, make sure the sprinkler covers the entire garden area evenly and doesn’t water things you don’t want watered, like your lawn furniture or windows.
• No matter what kind of garden you have or which watering system you use, infrequent deep soakings are better than frequent shallow waterings.

Overwatered Plant

Telling when a plant doesn’t have enough water may seem to be a snap, but keep in mind that there’s definitely such a thing as too much water. If puddles form in your garden or an area of it’s quite soggy, all the pores in the soil fill. When this happens, no free oxygen, which needs to get to the roots, is in the. Meanwhile, some plant diseases (like mildew and blight) travel via water and can easily develop and spread in soaked conditions. Sodden roots blacken and rot, and all the aboveground growth subsequently dies. Garden plants in these circumstances, of course, need less water.

Unfortunately, an overwatered plant looks the same as one that’s underwatered! The reason is that an overwatered plant is actually suffering from dehydration because the roots have been damaged by too much water (actually, too little oxygen, because the water has displaced the oxygen); the roots can’t absorb water, so the plant wilts. One difference is that overwatered plants don’t recover from wilt when you apply additional water, but underwatered ones generally do.

Gardening Australia Expo opens in Brisbane

If there is magic to be found at the bottom of the garden, one would be sure to find it at the Gardening Australia Expo this weekend.

The Brisbane Convention and Exhibition Centre abounded with wonders botanical, innovative and sustainable, with everything from water tanks, boutique compost and specialist plants for the dedicated gardener.

The most unusual plant on display was without a doubt the hybrid Aloes.

A cousin of the humble Aloe Vera found in most gardens, these unique blooms can go for six months without water and have an other-worldly names like Gemini, Topaz and Aries.

Breeder of the plants, Michael Dent said the blooms were complex, some having up to eight parent breeds.

"We launched them here in Queensland and hope to take them to other states soon," he said.

But not all the interesting plants at the show were botanical, as the brisbanetimes.com.au discovered talking to Mr Paul Plant.

Mr Plant, editor of subTropical Gardening Magazine, said his name was indeed the one he was born with.

Appearing keenly aware of the irony of having the name Mr. Plant and being a well-known figure in the horticultural community, he said he didn't have an especially keen affinity with greenery as kid.

"I just was the only one in my family that didn't instantly mow over everything my mother planted."

The expo runs from 9.30am - 4.30pm today and tomorrow.

5 tips for drought-smart gardening

By Tina Mast, Correspondent
The garden year is defined by many words and, as circumstances change, they change, too. This year's garden word, it pretty much goes without saying, is "drought."

At this point, that's no revelation, but as the buds burst on the dogwoods and green tips push up through the soil, many of us are considering how we want to garden in this year of water restrictions and drought-weakened gardens. Here are a few ideas for getting by when the going gets dry.

First, find some way to collect rain water. You have options at all price points. Whether you piggy back a bunch of retrofitted garbage cans together, buy pre-fabricated rain barrels, or have an above or below ground cistern installed, you can and should try to collect water. Even if you don't plan on doing a lot of planting, your existing plants may be quite weakened from the drought last year and will be much more susceptible to giving up the ghost this year.

In your container gardens, use water-holding granules or mats. The mats can be cut to fit containers, placed in the bottom, and planted over. During the heat of summer, it's helpful to keep saucers under your containers so that when it rains or you water, you have a little reservoir of water for the plants to draw from over the coming days. Deep saucers are even better than the standard shallow ones for this. This is a temporary technique, however. Do this in winter or during a wet season and you could have plants rot out on you if you don't dump the excess water periodically.

Many people are asking about drought-tolerant plants, and with good reason. Just bear in mind that, with few exceptions, drought-tolerant plants are not drought-tolerant the first year in the ground. If you plant them this year, make plans to water them regularly, too. Next year they'll reward you with their toughness and durability (probably just in time for a record wet year).

Make sure you get a nice 3-inch layer of mulch layered over your garden beds, as well. Mulch isn't just a nice way to pretty up the garden; no, mulch is your friend. It will help keep water from evaporating from the soil. It will smother emerging weeds. It will help keep soil and soil-borne diseases from splashing back up onto plants during what we hope will be frequent rainstorms. It will keep plant roots cooler in the heat of summer and nice 'n' toasty during winter.

It won't keep you from accidentally digging up your heirloom snowdrops as you try to find a place to squeeze in another plant or tell you where you last left your pruning shears, but other than that it's got you, dare we say it, covered.

Finally, don't hang up the trowel because we're having a drought. Gardens feed the soul, exercise the body, delight the senses, provide a place of respite, and give sustenance and shelter to the local wildlife (OK, so that includes voles and snakes). It's a fact, not a maybe, that there will always be some obstacle to overcome. So, as spring dons her rainbow attire, don't resist the urge the get out in your garden and get dirty. Go forth and dig!

On the dry side

If you know what to look for, you can figure out your plants’ watering needs. Plants actually prioritize when water-stressed, so look for the early warning signs:

1. If a plant isn’t getting enough water, flower petals and buds are the first things to be jettisoned (or fruit if it has developed), because making and maintaining them takes so much energy and water.
2. Next to go are the leaves, which shrivel.
3. Then the stems flop.
4. Underground, the roots go limp.

Obviously, if your garden is in this condition, it needs more water.

Tackling Watering Issues

Sure, without moisture, plants die. Everyone knows that. But you may not know why water is so incredibly vital. The answer is threefold, actually:

• Sufficient water pressure within plant tissues creates turgor, or rigidity, so the plant can stand up. A plant without turgor pressure collapses.
  
• Water keeps nutrients flowing through the soil, the roots, and the plant parts as they should; it keeps the show going.
  
• The show is the chemical process of photosynthesis, which you no doubt remember from biology class in school. The plant uses light, carbon dioxide, and water to make sugar (a pretty impressive trick).

Without photosynthesis, plants can’t grow or develop flowers or fruit. Keeping a close eye on your plants is easier said than done, of course, but the following sections tell you what you need to know, to keep in mind, and to watch out for when evaluating just how much moisture your garden needs.

How to apply mulch — and how much

If you’re ready to start applying mulch to your garden, here’s what you need to know to ensure you get the best possible use of your mulch:

• When you plant: Applying mulch right after planting something is easy. Use a shovel or scoop with a trowel. Spread the mulch over the rootzone area but not flush up against a plant’s base or main stem (which can smother it or invite pests or disease).
• Depth depends on the sort of plant. Annuals and perennials are fine with an inch or so of mulch; shrubs, roses, and trees need 3 or 4 inches or more.
• During the growing season: Add more mulch midway through the growing season or whenever you notice it’s depleted. You may have to get down on your knees or wriggle around a bit as you try to deliver it where it’s needed without harming the plant or its neighbors. Again, use less for smaller plants, more for bigger ones.
• In the fall or for winter protection: Depending on the severity of your winters and the amount of snow cover you expect (a blanket of snow can act as a protective mulch, actually), you want to cover an overwintering plant well. You can cut down perennials first and then practically bury them under several inches of mulch. You shouldn’t trim back shrubs and rosebushes at this time, but you don’t have to be as careful as you were with midsummer mulching because the plant is no longer growing actively. For freezing winters, 6 or more inches around the base of these is good.

These amounts are guidelines only. You have to tailor them to your climate, growing season, and specific plants.
To limit erosion, don’t excavate large areas that are on a slope without planting or at least mulching soon, especially during the spring, when rainy weather can cause washouts.