Potting By Water Zone

Plant lovely containers to match specific water zone needs. Responsible gardening hinges on good water management to get the best out of an expensive and scarce resource, and this also applies to container gardening. With this in mind, I hunted around our office yard for old pots, repainted them, and went shopping for plants to match four typical watering zones.

High Water Zone Requirement

In the garden you would usually pick only a few plants with high water requirements, to keep the water-guzzling zone as small as possible. But when planting up a container you can go to town with thirsty seasonal colour. If looked after, a pot like this can last for 3-4 months (or even longer) before you will need to replant it with a fresh flower combination.

Hot Tips

Pick a large, shallow container with a wide mouth to allow lots of space for many different types of seasonal annuals and a few perennials – the ones planted here want full sun.
Use the best quality potting soil, to which a water retention product has been added. (This is good practice for all containers, no matter the water requirements.)
Good drainage is crucial, so make sure that all the container’s drainage holes are open. You can also add a layer of drainage stones at the bottom.
All these plants require moist soil, so be prepared to water every day in hot weather.
Nipping out the dead flowers and feeding weekly with a water-soluble fertiliser will keep your miniature flower garden in top shape.

Flowery Ingredients
For this combo, we used typical spring- and early summer-flowering annuals and perennials.

Delphinium hybrids
Ocimum Basilicum Herbalea ‘Dark Lady’ (perennial basil)
Osteospermum ‘Voltage Yellow’
Verbena EnduraScape ‘Red’
Verbena Quartz mixed
Dianthus Diamond ‘Purple Picotee’
Dianthus Ideal select mix
Nemesia Sunsatia hybrids

Medium to High Water Requirement

Although most perennials need lots of water to look their best, some won’t sulk and die off if left a little high and dry for a few days. The two plants picked for this pot have another good characteristic in common – they will grow equally well and produce as much colour in full sun or in dappled shade. This makes it a good combination for a busy gardener who loves low maintenance containers filled with graceful foliage plants.

For this combination we used two tough favourites –
Chlorophytum (Anthericum) Saundersiae Variegata ‘Starlight’ is a bright and breezy hybrid of the indigenous Anthericum and was released in 2014. The white stripes, flower stalks and flowers are perfect for brightening dull areas in sun or shade all year round. This graceful, grass-like plant can be used for mass planting in the garden, or as a focal plant in a pot. It will reach a height of about 75cm.

Alternanthera Bettzickiana ‘Tricolour’ (also known as Alternanthera Amoena ‘Tricolour’) has been around for donkey’s years and is widely used as an ornamental ground cover due to its mottled foliage colour in shades of maroon, burnt orange, golden yellow and bright green.

Hot Tips

Although both of these plants are known to be quite tough and fairly drought resistant, they will grow better if watered regularly and fed during spring and summer.
Remove spent flower stalks and old leaves from the Anthericum. Prune back the Alternanthera if it becomes leggy or starts producing its insignificant white flowers, as this can cause the pretty foliage to lose its glowing shades

Medium to Low Water Zone Requirement

Cordylines have always been used as strong focal plants because of their architectural growth habits, with dense rosettes formed by strap-like leaves. They have lost a little favour over the years, but since the recent appearance of some very colourful new hybrids, they have retaken their place in our hearts.

Any Cordyline is a good investment, as they are easy to grow and resistant to many gardening problems like a scarcity of water, insect infestations or wind. They are magnificent candidates for pots that need little or no pampering. We paired two Cordylines with something more exotic for tropical splendour –

Cordyline Australis ‘Torbay Dazzler’ can grow into an evergreen, palm-like tree branched into several dense rosettes of green, sword-shaped leaves with a strong cream variegation and a pinkish mid-line on new leaves.

Cordyline ‘Red Fountain’ is a dwarf, clump-forming Cordyline with ruby or burgundy strappy leaves that can reach 1 m in length and cascade backwards into a rounded shape. This colour beautifully complements other plants in a garden or container.

Lotus Berthelotii (Parrot’s Beak) was the perfect choice to use as a dramatic filler plant between the Cordylines in this tall pot, as it softens the overall look. The delicate, silvery foliage chains cascading over the rim belie the fact that this is a tough plant that hates being over-watered. Both Cordyline cultivars will in time produce delicate sprays of sterile flowers in summer, but it is the fiery shade of the lotus’s lobster-claw-like blooms in burnt orange or red that will turn heads in spring or autumn.

Hot Tips

Watering once or twice a week in hot weather is more than enough for these plants when they are established.
Too much sun can scorch the Cordylines’ leaves. Simply move the container to a spot with a little dappled shade during the hottest
Regularly pull or cut off older leaves at the base of the Cordylines’ rosettes and trim the Parrot’s Beak’s long side branches back to encourage denser growth.

Low Water Zone Requirement

‘Water wise’ container gardening does not limit you to wizened, old, ugly plants! Amongst our indigenous succulents and ground covers lurk fantastic shapes and colours. Also, remember that no plant (even the toughest of the tough!) can be held captive in a pot without a drink of water every now and again

Resist the drought…
1. Euphorbia Mauritanica (Golden Splurge) is a spineless shrub up to 1.5 m in height that has a wide distribution across the country. It is a fast-growing and popular subject for rock gardens and is extremely drought resistant. The cylindrical side branches are smooth and light green in colour, and small yellow flowers appear on their tips in spring. When injured, these branches produce milky latex that can cause skin irritation, so wear garden gloves when handling them.

2. Gazania Rigens New Day ‘Strawberry Shortcake Mix’ is a series of compact and sturdy Gazanias bred specifically for containers and other small spaces. They have a long flowering period with a good drought tolerance but replace them every now and again with fresh stock for prolonged flower power.

3. Sedum Reflexum ‘Blue Spruce’ is a low-growing, spreading succulent with ice-blue leaves that add a lovely colour contrast between other water wise plants. This sun loving plant produces small yellow flowers in summer. This stone crop is a perennial that will stay around for a long time.

What is a Water-Retaining Product?
Water-retention polymers and commercial soil conditioners are designed to improve water retention in pots and garden beds. Water crystals absorb water and provide a reserve of moisture around the plants’ roots. Granular soil wetters and conditioners improve soil structure to retain water, reducing water use and wastage.