Your Gardening Questions Answered
Earlier this year we asked our Facebook fans to share their biggest backyard problems, and now we’ve got the solutions...
5 July 2018
From lawn loathes to pest control, you shared your biggest gardening challenges and most pressing questions and now we've got the answers. To help you out we teamed up with Horticultural Consultant for Mr Fothergill’s, Marianne Cannon, to get to the bottom of some common issues. Marianne can also be caught on her gardening radio show, Real World Gardener, for more great gardening advice.
Is there a cure for curly citrus leaves?
How to cure curly leaves is one of the most frequently asked questions I get about citrus trees. Unfortunately, the short answer is, once they’re curled there’s no going back. This pest is known as citrus leaf miner and it causes those ugly distorted leaves with silvery trails that appear in the leaf tissue.
The leaves curl because of a tiny moth laying its eggs in the new leaf growth. When the eggs hatch, the larvae feed on the leaf tissue then tunnel their way out. By the time you see the damage, the pest has long gone. The best control is prevention. Meyer lemons are particularly susceptible.
There are several ways of tackling this problem, but it’s all to do with timing. As soon as new growth appears on your citrus trees, start planning your spray regime. You can use any horticultural oil, such as Pest Oil, but there is also an organic solution. One option is an oil such as Eco Oil, which is organically certified; the other is to hang leaf miner traps in your tree. These baits contain a pheromone that attracts and traps the male moth. You also need to spray when new growth is about 1cm long and reapply every 2-3 weeks. January and February are crucial times to spray.
I have little black insects on my cherry and plum trees, what are they and how do I get rid of them?
This is pear and cherry slug, which is the larvae of an adult sawfly. The larvae cover themselves in a green slime, so they appear like slugs, to make themselves unattractive to predators. The name sawfly refers to the saw-like ovipositor (an organ used to deposit eggs) they use to slice leaves so the eggs may be laid inside.
The fully-grown larvae drop from the tree and pupate underground. The adult sawfly later emerges from the pupal case and climbs from the soil to mate and lay eggs on the leaves of the host plant. They don’t just stick to plums and cherries but go for apple, pear and quince trees, too.
What you can do is some or all of the following:
• The larvae overwinter in the soil under the tree, so clean up that area as much as possible and invite some chickens to go scratching around the dirt.
Not got any chickens? Then here are some other tips:
• Squash them if there aren't too many.
• Hose them off the leaves with a strong jet of water.
• Throw ash, flour or powdered clay over the tree. Make sure the wind is going in the opposite direction so you don’t get it all over yourself.
• Band the tree with a horticultural glue to prevent them climbing back up.
• Encourage natural predators such as paper wasps, hoverflies, lacewings, spiders and insect-eating birds.
• Spray with a pest control containing Spinosad. Spinosad is a biological insecticide.
What’s the best way to pack my plants for transportation when moving house?
Firstly, be aware that if you’re going interstate quarantine regulations apply. You must obtain approval from the relevant departments as not all states allow plants to move across their border.
Several weeks before the big move, prune your plants of any dead leaves or leaves that look like they will get in the way. Just prune lightly and treat for any pests or disease. If there are any branches that look like they will get snapped off, use soft ties to reign them in. Transfer them into plastic pots if possible to make lifting easier. If this is not possible, make sure the terracotta//ceramic pot is not cracked, so it doesn’t break during the move. Give the plants a good watering with seaweed extract about 5 days before the move. You don’t want to be moving plants with heavy wet soil or dirty water getting on to your furniture in the moving van.
Removalists prefer you to pack your plants in boxes. Allow for ventilation if your plants are being transported a long way.
For prickly plants such as bromeliads and cacti, wrap the outside with several layers of bubble wrap. For more delicate plants like African violets, where leaves can be easily knocked off, you need to find some large plant trays or shallow boxes and scrunch up newspaper to buffer the plants.
For hanging baskets, pack into boxes. Use scrunched up newspaper, or any other packing material that you have, to prevent them from moving.
When your plants arrive at your new home, give them a good water.
I’ve tried and failed to grow herbs; how do I get off to a good start?
Herbs are easy once you get the hang of their requirements because they don’t actually need much maintenance. You don’t even need a herb garden as a lot of herbs can be grown in pots on a sunny windowsill.
If you’re starting from seed, some herbs will seem devilishly difficult to get started, however basil is by far the easiest herb to get going with. So easy, that old seeds will germinate so you never have to worry about leftover seeds being wasted.
The best time to sow basil seeds is spring onwards.
1. Fill a punnet with seed raising mix nearly to the top. For best results, moisten the seed raising mix before sprinkling on the seeds. Tip: If the mix doesn’t seem to let water penetrate easily, then it needs to soak.
2. Scatter over the seeds.
3. Cover the seeds very lightly with more seed raising mix (no more than 6mm) and mist either with a spray bottle or the mister setting on your hose spray nozzle.
4. Place the seeds in a mini greenhouse or cover with plastic wrap until they germinate. The seeds should germinate within 5-10 days.
5. Once the seedlings have grown their second set of leaves, they’ll be ready for transplanting. Basil likes to grow in rich soil if in the garden, or in a good quality potting mix if grown in pots inside. Make sure that it doesn’t dry out too much. Pinch off the top leaves as the basil grows to make it bushier. If flower heads start forming, pinch these off too so that the basil plant keeps producing leaves, otherwise, it will set seed and stop growing.
Sowing rocket or arugula
This is another easy herb to grow, the seeds of which can be scattered in the veggie bed or herb garden with no trouble germinating as long as the temperature is above 10°C. Part-shade is OK too. Simply pat the seeds into the soil. If the weather is warm, the seeds will sprout in a couple of days. You’ll be able to pick the leaves within a few weeks.
When the rocket is about 8-10cm long, you can either cut the whole plants (they will re-sprout) or start harvesting a leaf here and there. Either way, remove any flower stalks that appear.
The next herb you could try that is relatively easy to grow is coriander, which only takes 3-4 weeks to mature.
One thing to remember about coriander is that it prefers to grow in the cooler months of the year.
This is a herb that grows with a deep taproot, so it’s best to start it off in a garden bed or large pot. For growing in pots:
1. Fill the pot with a good quality potting mix to 2cm from the top, then add seed raising mix to top it up.
2. Moisten the soil mix first, then sprinkle over your coriander seeds.
3. Cover with 6mm of additional seed raising mix and mist with a spray bottle or the mister setting on your hose spray nozzle. Tip: If you’ve ever wondered why your coriander suddenly starts flowering before you’ve even harvested the leaves, it’s because either the weather is too warm or it was transplanted. There’s no going back, so you’ll have to start again in cooler weather.
This herb is slightly more difficult to grow, but still worth a try, especially flat-leaf parsley (sometimes called Italian parsley). The best time to sow parsley is in spring through to autumn.
There are a few tricks for getting parsley seeds to sprout:
1. Parsley seeds need warmth to germinate, so start them indoors if your district experiences a cool start to spring. Parsley will germinate best at temperatures from 5-32°C.
2. For growing in pots, fill the pot with a good quality potting mix to 2cm from the top. Then, add seed raising mix into which you will sow the parsley seeds. Tip: Speed up the germination process by soaking the seeds in warm water for up to 24 hours before sowing. Even then it can still take up to three weeks. Another method is to pour boiling water over the punnet or pot with the sown seed.
3. Cover the seeds with 1cm of seed raising mix.
4. If you’re growing parsley in pots, water regularly, as pots dry out quickly, especially the terracotta ones.