Wilting leaves. Browning edges. No one wants to be confronted with an ill-looking houseplant – a reminder, perhaps, of the neglect we’ve subjected it to. Still, plant trouble can happen to even the best of us. To help with diagnosing a few common, fixable issues, we consulted horticulturalist Tammy Huynh.CRISPY BROWN LEAVES If your plant is sporting crunchy brown leaves, it’s likely sunburnt from intense direct light. Move it to a place with softer lighting and it should recover (feel free to lop off those shabby leaves too). If you’ve got leaves browning round the edges, this signals that the plant is hungry for humidity. Many of our favourite indoor plants originate from tropical regions of the world and thrive in rainforest-like conditions. The air in our homes is often much drier (especially come winter when the heater’s on), so our browning plants appreciate any boost to humidity they can get. If you have the budget, you can invest in a humidifier. But the easiest and cheapest solution is to group your plants together. “Sit your devil’s ivy with your monstera and philodendrons, for example,” Tammy says. “They’ll create a little microclimate immediately.” Another solution is to fill a saucer with pebbles and water. Sit your plant pot on the pebbles – as the water evaporates, it’ll increase humidity. Those of us who love misting our plants may be disheartened to learn that it’s a band-aid solution. While it never hurts to mist, Tammy advises that it won’t solve the problem on its own. “You’d have to keep misting throughout the day to maintain a certain level of humidity,” she says. Same goes for placing plants in the bathroom. With the window open or fan on, any humidity you’re hoping to gain from a steamy shower dissipates quickly. In general, plants with thinner leaves require extra humidity. Succulents and cacti, however, can rot from too much moisture, so make sure to separate them from your tropical plants.CURLING LEAVES If your plant’s leaves are curling or rolling inwards, this means it’s trying to prevent moisture loss and evaporation. Chances are it’s thirsty too. To confirm, check your soil – if the top 2.5 centimetres are dry, give it a good water. If you notice that the water is running out of the pot quite quickly, this suggests that the soil is not retaining moisture and that the plant could do with a repot into fresh soil. To address the dryness issue, it’s also worth boosting the humidity (use the methods outlined above) and checking to see if your plant is sitting in a spot that’s too sunny or draughty (this could be causing it to dry out quickly). Remember to check your watering habits. If you don’t water deeply enough, it can lead to dehydration long-term. If your plant’s leaves are curling but the soil is muddy, this suggests you’ve overwatered – and now the roots are potentially rotting and no longer able to absorb water. To remedy, repot your plant into new well-draining potting mix.LEAF DROP It’s normal for plants to shed old leaves every now and again. A single leaf dropping should not be cause for alarm, especially if you can see new growth emerging (this means your plant is focusing its energy on fresh shoots and letting go of the old). It’s also not uncommon for plants to lose a leaf after you’ve brought it home from the nursery. “At the nursery, it's basically living in a plant spa with the best conditions,” Tammy says. “The conditions inside your home are different, so it’s just adjusting and climatising. Nothing to worry about.” If your green child is suddenly surrounded by a pile of leaf litter however, you’ll need to investigate the issue pronto. Tammy suggests going through the usual plant-health checklist. “Check you’ve got it in the right spot, how often you water it – it may be too often or too little – if the seasons have changed and you’re blasting aircon or the heater. That will help you understand the root cause of the problem.” As tempting as it is, Tammy urges you not to whack your glum plant outside – it’ll go into shock from the sudden change in light and temperature.YELLOW LEAVES Let’s start with the good news: older leaves on a mature plant can turn yellow and drop off; this is natural and nothing to worry about. If your plant’s leaves are progressively yellowing, this is a tad more complicated. The culprit could be overwatering, underwatering, a lack of nutrients, or even fertiliser burn. “It’s like if you went to the doctor and said, ‘My elbow hurts.’ They’ll say, OK, well what have you been doing?” Tammy says. Zeroing in on the issue may be a process of elimination; Tammy recommends starting with light. Where has your plant been sitting? Is it getting the right amount of sunlight? Shrivelled, crispy yellow leaves suggest too much harsh sun and heat and not enough water. Limp, mushy yellow leaves may mean it’s had too much water and maybe needs a brighter room. Pick one potential solution at a time and give it at least a week to adjust to the new routine. Monitor any changes once you’ve tested a hypothesis. Ideally, your plant will soon perk up, but if you don’t spot any changes, this isn’t necessarily a bad sign – your plant may simply need more time to stabilise. If it’s clearly looking worse and all-round sickly, you’ll need to keep troubleshooting (check soil moisture, the drainage of the pot, review your watering schedule). As for those unsightly leaves – feel free to cut them off.

A FEW NOTES ON WATERING 

- Uh, oh, realise that you’ve been underwatering your plant? Give it a water ASAP and make sure you water enough so that you can see water running through the bottom of the draining holes in the pot. To check if your plant needs a drink, insert your finger into the top 2.5cm of soil. If the soil is dry, water. If it’s moist, let it be.

- Given your plant too much love? “If you’ve accidentally watered it two days in a row, just let it dry out, it should be fine,” Tammy says. But if you’ve consistently overwatered and the soil is soaking and dripping – even after you’ve let your pot dry out for a while – you’ll want to repot. Check the roots for signs of root rot while you’re at it too.

- Plants love rainwater, but there’s usually nothing wrong with tap water either. Unless you live somewhere with hard water, Tammy’s opinion is that it’s not worth going out of your way to use distilled water. “If it’s raining, I always try move my plants outside or collect the rainwater,” Tammy says.

Tammy Huynh is a horticulturalist, the owner of gardening business Leaf an Impression and a presenter on Gardening Australia. See more from Tammy at leafanimpression.com.au or on Instagram at @leaf_an_impression.

This handy guide was featured in our one-off gardening mag, Evergreen. To get your mitts on a copy, swing past the frankie shop or visit one of our lovely stockists.