Feeling that chill in the mornings lately? Needing to dig out those jackets from the bottom of the cupboard? Yep - the colder weather is here, and if you're feeling it, you can bet your plants are too. In fact they've been feeling it long before you.
You've probably already noticed autumn flowers popping up in the garden and cosmos in the park, and I've even spotted my first Aloe flower, and Protea!
While outdoor plants naturally adapt to the changing weather, how do we care for our houseplants in autumn?
1. Prune damaged leaves
While heavy pruning and shaping should be done in Spring, if you notice leaves that are rotten, yellowing, holey or just nasty, you can trim these off close to the stem to reduce the amount of energy your plant needs to put into these leaves. Plant energy is going to be lower as the days get shorter and the sun weaker, it's best for plants not to overexert themselves on dead, wasted leaves.
If you have any vining plants like the Monstera adansonii or Raphidophora tetrasperma, check if they need staking, to help support your plant's stem as it grows upwards, preventing it from leaning towards the light source as the sun gets weaker.
Most houseplants originate from warm jungle climates. Temperature is one of the most important factors to keep indoor plants happy in cool weather. Ideally, indoor plants shouldn't be exposed to anything below 15°C. Calatheas and Alocasias are especially sensitive to cold and can even go dormant, dropping all their leaves if too cold. Ficus also need to be kept warm or they will suffer leaf drop.
Check if any plants are near an open window or door and exposed to draughts. Close windows and doors at night. Or you may have to move your plant somewhere warmer. If plants are on a cool tiled floor, you can also put them on a warm blankie.
Mulch (a layer of un-composted organic material like bark chips, leaves or straw on top of the soil) has a myriad of benefits including
- Regulates soil temperature, helping the root system stay cool in summer and warm in winter.
- Keeps away pests
- Provides a slow release of organic nutrients as the material breaks down
- Helps retain soil moisture & reduces evaporation
A sprinkling of bark chips now will help your plants retain warmth in the colder months.
TIP: When mulching, be careful not to suffocate the stem by heaping the material around it. Leave a slight gap around the stem.
4. Beat the bugs
Autumn means dry air, less rain and hot days - the perfect conditions for spider mites.
- Spider mites are often invisible to the eye, but leave webbing over the leaves. A tell-tale sign is tiny faded spots or stipplings on the leaf where the mites suck the plant cells. Sometimes you can see the mites, they look like teeny tiny round reddish-brown or black bugs resembling poppy seeds.
Stippling from spider mites
The best way to treat spider mites is early detection, then spray and wipe leaves, top and bottom, with an organic neem based insecticide, like Bioneem. Ludwig's also has a specially formulated Canola oil based spray for spider mites.
Spraying plants with a soapy solution of a small amount of dish or hand soap mixed in water helps to prevent mites. Increasing moisture in the air and misting plants with water will help combat the dry conditions that the mites love.
5. Soil & fertilising
You can give your plants a final feed before winter. Also check the status of the soil. Does the soil seem constantly dry and losing its rich dark colour? Has the plant been in the same soil & pot for over 8 months? While you should postpone re-potting for spring, you can top up your plant with a layer of fresh potting soil, to keep your baby happy and nourished.
6. Water and humidity
Check your watering schedule as your plants will need less frequent watering as the weather cools. Check water temperature, adding a bit of warm water if the tap water is seriously cold. Don't leave plants outside if spraying with a hose.
While your plant will need less watering, it will need more humidity as the air gets drier. If your lips are feeling dry, imagine how your plant's leaves are feeling. Increasing humidity is essential for some plants like Calatheas and ferns to prevent brown leaves. Read our humidity tips here