Achieve Planting Success

Still in high summer, but no harm in planning forward. So, let’s green our thumbs..

If you have achieved planting success you now probably have a pretty garden that makes you happy and content without asking too much more of you. If not, take heart as planting success relies on easy words like ‘climate’, ‘planning’, ‘position’, ‘preparation’ and ‘care’.

Climate concerns for planting success

One of the main reasons why some plants sometimes disappoint the gardener (even if pampered endlessly) is that they cannot adjust to difficult climatic conditions. Although you can create artificial microclimates in any garden to please one particular must-have plant, it makes no sense to do it for an entire garden. If you garden in an area that is prone to heavy winter frost and cold winds, think about the following choices:

Deciduous plants will go into winter dormancy, shedding all their leaves and hardening the cells in trunks and branches to survive. Indigenous trees like Combretum erythrophyllum (bush willow) and Dombeya rotundifolia (wild pear) are good examples, and they aren’t boring as they will either give autumn leaves or spring blossoms.

Evergreen plants with tough leathery leaves can be used as nurse maids, protecting tender plants from cold winds and frost. Use Dovyalis caffra (kei apple), viburnums, Nandina domestica (heavenly bamboo), Buddleja salviifolia (sagewood) and Escallonia ‘Iveyi’ extensively as screening or hedging plants. These are also good choices for frost-free coastal gardens in both summer and winter rainfall areas.

Winter sleepers die off above ground, but their root systems tick over below the soil to emerge once again when temperatures rise. Examples of these clever survivors are shasta daisies, gauras, cannas and hostas. Simply cut them back at the beginning of winter and mulch them with straw. Mark their sleeping places with sturdy labels on stakes to remind you where they are.

Bulbs: Bulbs that flower in late winter and spring, like freesias, daffodils, ixias, anemones, tulips and ranunculus, love the cold, are easy to grow and are guaranteed to flower successfully if watered deeply every four days after emerging. Plant these bulbs from April to the end of May.

Cold-hardy annuals: Sow great swathes of African daisies, bokbaaivygies, Virginia stocks, poppies, nemesias and linarias directly, and plant seedlings of violas, pansies, primulas, petunias and Iceland poppies.

Clever landscaping: Identify potential frost-prone areas in your garden and change the layout into a design featuring hard elements like gravel and steppingstones. Soften the look with lots of grasses like Carex (sedge), Festuca (fescue), restios like Elegia tectorum (Cape thatching reed) and Aristida junciformis (nGongoni grass). All are frost-hardy and will add winter grace and summer pleasure.

If all else fails… Drive around in your neighbourhood to see what is growing happily in other gardens and plant the same. 

Plan before planting

For planting success you need to take your time when planting up a new border with different plants. Set them out and, if necessary, move them about until you are satisfied that they will look good together. When I see a plant I like, I usually write its name with a Koki pen on those long-handled plastic plant labels that nurseries use to label their plant lanes, to give me a chance to swot up on them properly, before actually buying and planting them. This practical tip also stops you from planting a ‘fruit salad’ instead of aiming for a dramatic ‘less is more’ look, with small groups of the same plant repeated here and there. And, if your budget gives in, there will still be a label sitting there to remind you what to buy next month!

Positioning is vital

  • Although you can transplant certain shrubs growing in the wrong position in autumn, some trees and large shrubs like bougainvilleas, fynbos and conifers dislike root disturbance. When selecting a site for them, very carefully consider their mature size. Once they are established, moving them is seldom successful.
  • Deciduous shrubs and trees with gold- or creamcoloured leaves, like maples, should get a special spot where they will be seen but will be protected by partial shade on hot summer afternoons, to prevent the pretty foliage from scorching and spoiling their autumn splendour.
  • To prevent a dull winter look, surround barestemmed deciduous shrubs like berberis with cheap and hearty evergreen groundcovers like Viola hederacea or Asystasia gangetica (creeping foxglove).
  • When planting annuals, avoid doing it in straight lines. Staggered rows or clumps of colour are more effective.
  • When replacing a dead or diseased plant, never replant in the same hole. Dig a new hole to prevent possible contamination or remove as much of the soil as possible and replace with other soil or commercial potting soil. Never use strong disinfectants like Jeyes Fluid thinking that it might kill off harmful soil pathogens. It is bad for the soil and will kill off friendly soil organisms too.
  • If you want to plant a creeper against a wall to hide it, do this at least 30cm away from the wall and rather attach it to a trellis panel that you can pull away now and again to check for insect infestations like red spider mites hidden behind it.
BUY QUALITY: Early autumn is a good season to plant new fruit trees as they will have all winter to become well established before active growth starts in spring. Although it is fun to grow fruit trees from pips (like the old avocado pip suspended over water on the kitchen windowsill), it is not advisable as the trees are seldom good bearers, if at all. And if fruit does appear, it could take many years for it to do so. Modern fruit-tree cultivars grafted on disease-resistant rootstock will bear much faster.

Preparing for planting success

Square hole or round hole? The shape of a planting hole in well-prepared soil is of no consequence to the plant, as long as it is twice the diameter of the size of the plant’s root ball and is deep enough to accommodate it comfortably.

Don’t… Toss a lot of compost in the hole. In heavy soil you might create a sump. Rather use the compost to enrich the excavated soil with an added soil amendment, and then backfill the hole to planting depth.

Root food: Phosphorus is an essential nutrient for plants. It aids fruiting and stimulates early root formation and strong root growth.

Bonemeal is organic and made from ground animal bones. It breaks down slowly to release nutrients over a long period. Mix it into compost-enriched excavated soil.

Superphosphate is a fairly fast-acting inorganic chemical and should also be mixed well into the backfilling soil, following the instructions on the package. Stick to the instructions on the bag – too much of it can cause root burn.

Release the plant gently

Modern horticulture means that plants are not sold bare rooted anymore, but in plastic pots or nursery bags. The reason is so that you can actually plant anything in any season!

  • Before planting, water the plants deeply or plunge them into a bucket of water for quite a while if they have been hanging around waiting for you!
  • Don’t pull a plant from a nursery pot by its stem as this can damage the roots. If it is stuck in a pot, try dunking it in water again or run the blade of a knife between the soil and the pot. If still stuck, cut open the sides of the plastic pot with a penknife.
  • If a container-grown plant has become root-bound in its bag or pot (there will be a nest of white roots growing in a circle). Gently disentangle the roots and spread them widely before settling the plant into the planting hole. It helps to make a little soil heap at the bottom of the hole for the plant to sit, on while you are spreading out the roots.

Planting success requires aftercare

  • Water newly planted plants thoroughly and immediately afterwards, even if rain is expected. Water eliminates air pockets and ensures that all the roots come into contact with the soil.
  • Remember to mulch your plants after planting and watering, but keep the material away from stems.
  • When planting a tree or a standard plant it can sometimes be difficult to hold it straight without help while trying to fill up the hole. Overcome this by tying the plant to a sturdy wooden plank or broom stick that is longer than the width of the hole at exactly the point where the trunk is emerging from the soil in its nursery container. Place the plant in the hole, resting the support on either side of the hole. Fill up the hole, firm the soil down, remove the support and water well. Remember to hammer in stakes for support before filling the hole!
  • Protect young seedlings by placing some slug pellets next to each plant after watering in.
  • To get the best value for money and lots of flowers, deadhead annuals frequently and feed them every two weeks with a water-soluble fertiliser.
The Gardener