Plant drought hardy containers

Materials:

• plant container (at least 25 litres)
• prepared soil mix
• fertilizer (14-14-14 or 20-20-20)
• hydrophilic crystals
• light sand or pebbles (for mulch)
• drought-tolerant perennials, such as:

Rosmarinus officinalis – (rosemary) zone 8
Artemisia ‘Powis Castle’ – (wormwood) zone 7
Coreopsis verticillata ‘Moonbeam’ – (tickseed) zone 3
Thymus pseudolanuginosus – (wooly thyme) zone 4
Festuca glauca ‘Elijah Blue’ – (blue fescue) zone 4
Sempervivum – (hens and chicks) zone 5
Euonymus fortunei – ‘Emerald Gaiety’ zone 5
Vinca minor – (periwinkle) zone 4

Container gardening and the concept of planting for drought resistance are natural companions. Within the confines of a container, hot and dry conditions can often develop as soil temperatures tend to fluctuate greatly, and plant roots quickly consume the available water. Such trying conditions can easily kill off your plants unless you can find ways to minimize the extremes that accompany container gardening. Armed with our planting instructions, however, you can create a beautiful, drought-resistant perennial container garden that will look great from one year to the next – with minimal care.

Start your container with a good, balanced soil, combined with a selection of proven drought-resistant perennials. For our containers, we selected some silver-leaved and aromatic plants that generally show high drought tolerance and are good choices for hot, dry soils.

1. Purchase the largest container you can afford, ensuring it is at least 25 litres in size. Your container should be large enough to accommodate perennial growth for two to three seasons without having to be replanted. Every time you divide or replant, your perennial will need time to re-
establish itself in order to become drought resistant (no plant will be drought resistant until it is established). Cover the drainage holes in your container with pebbles to prevent soil leakage.

2. Perennials differ from annuals in that perennials develop larger, more robust roots that will go deeper into the soil to establish themselves. A combination of 1/3 premixed soil, 1/3 compost and 1/3 sand is one suitable soil mix for perennials, as the sand helps to anchor their heavier roots. Use a purchased soil mix rather than garden soil to ensure the best drainage and water retention. Mix into the soil a slow-release fertilizer such as 14-14-14 or 20-20-20.

3. Even out heat and moisture levels in the root zone by adding hydrophilic crystals. These crystals swell and soften as they absorb water, providing the container with an additional source of moisture. Alternatively, line the inside of your container with a section of newspaper. Newspaper also holds moisture and will help reduce stress to the roots near the outside of the container.

4. After you have positioned your plants and watered them, add a light-coloured mulch to decrease evaporation and prevent heat build-up in the dark soil. Either light sand or pebbles will work, but a sand mulch will allow for the development of the crown of your perennials. As the plants mature and cover the surface of the container, the sand will eventually sink through the soil.

By not having to replant your container every season, your perennials will not only require less watering, but they will have a chance to flower as well. Keep in mind that it will take at least one season for your plants to become truly drought tolerant.