I’ve just spent a few hours feeding my houseplants (a nice task for the weekend as Monty would say) and thought I would share some HPH tips I have picked up along the way. The first time I remember being taught about plant feeding was sitting on a stool in my grandpa’s greenhouse as a girl. It’s the same stool I now have in my apartment with my ZZ plant on it! Grandpa always grew tomatoes and explained to me that these plants need a special type of food in order to grow big and healthy… and of course to make lots of lovely fruit! He had an array of bottles in a box, with different things for his houseplants and garden plants too. I was very intrigued by these tinctures.
Whenever I talk about feeding plants to friends or clients, I always picture this, and it reminds me that plant care doesn’t have to be complicated or scary, and some simple pointers are usually the best way to start. In subsequent posts we can delve a little deeper, but lets begin with the basics:
1. Measure, measure, measure Over fertilising can damage your plants by causing scorching and will do more harm than good, so always follow the label instructions carefully.
2. Rest Only feed your houseplants in Spring and Summer; I feed every 7-10 days between April and October. When your plants are resting or dormant, they need less water and no feed, just think of it as a break for you as well as your plants!
3. Check the soil If the potting mix is quite dry, the plant should be watered lightly before feeding, otherwise fertiliser can burn and damage the roots.
4. Be careful after repotting If you are using a compost based potting mix, be careful after you have repotted your plants because some compost contains slow release plant food, the label on the bag usually says something like ‘feed for up to six weeks’. So make sure you aren’t ‘double fertilising’ these plants. In addition, if you have recently repotted or carried out any root pruning, avoid feeding for a few weeks.
5. Think about NPK Balance For foliage houseplants I like a NPK balanced ‘standard’ feed (which basically means there is an equal relative amount of each nutrient in the mix). These figures are usually written on the front or side of the bottle (they don’t always say NPK but they are always written in that order; sometimes just as a series of three numbers). NPK stands for Nitrogen – Phosphorus – Potassium and almost all feeds contain a mix of minerals/ trace elements too. Here’s a short summary of what these nutrients do:
Nitrogen (nitrates): helps foliage plants stay green and rich with the production of chlorophyll; if you have yellowing leaves or leaves with yellow spots, this can signal a lack of nitrates in the soil. (LEAVES)
Phosphorus (phosphates): helps the plant to develop strong roots and can help the plant to remain strong and fight disease. Weakened plants that are low in phosphorous can be more susceptible to pests. (ROOTS)
Potassium (potash): is important for the production of flowers or fruit and for strong stems. Potash rich fertilisers are sometimes called ‘ tomato-type’ fertilisers because this is what is given to tomatoes when they start to develop fruit. (FLOWERS)
It’s worth noting that different plants have different requirements; for example, to encourage growth and lovely blooms for cacti and succulents, pick a feed that is lower in nitrogen (too much nitrogen can actually make things flower less!) I’ll go into different types of fertilisers in a later post.
Here’s a graphic as a reminder of the above information:
Considering these factors can help you understand your plants and keep them healthy and happy! Hope you found this post helpful,
Thanks for reading and to my customers for asking me to put this post together,
2 replies on “How to feed your houseplants”
I find that with my big and old houseplants that have taken up all their space to grow, it is best to just give them enough fertilizer to keep them green and healthy, but not to promote growth. Eventually, they get taken out and cut back, but I like to delay the need for that.
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Yes, I agree Tony, with my bigger plants I do this too. There’s only so big the larger plants can grow in a home before they start to take over!
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