A Harriet’s Plants guide to feeding house plants
How to care for Roots, Shoots, Flowers & Foliage
2020 saw an exponential increase in house plant sales, which means there are plenty of new house plant parents out there that may need a little guidance on how to ensure their plant babies thrive. Knowing how, when and what to feed your house plants can be a challenge to even an experienced grower as each plants needs are slightly different. This can make the whole process rather overwhelming.
Here’s my top tips to making sure your plants are in tip top condition.
Feeding your plants is fun!
Lets feed our plants and learn together.
Horticulture 101.
Alongside the basics for photosynthesis i.e sunlight and water, all plants need 3 basic minerals for healthy growth. These are Nitrogen, Phosphorous, and Potassium, known in gardening circles as NPK. Nitrogen (N) is needed for healthy leaf growth and has similar benefits that protein has in humans. Nitrogen is what makes stalks grow strong but you can have too much of a good thing and it is important to pay attention to quantities as excess Nitrogen can decrease a plants immunity and ability to fruit. Phosphorous (P) is essential for root development, it strengthens cell walls and helps your plants to fight off pests and diseases. Phosphorous also improves flowering by strengthening tissues and can even make edible plants taste better. Finally, Potassium (K) is important for roots and seed production. Potassium is sometimes referred to as potash and it helps plants tolerate temperature changes. Be warned, excess Potassium prevents the absorption of other essential minerals. All plants need other minerals alongside the three mentioned above, such as calcium and magnesium, but when you can remember NPK it will help when choosing the right formula. Each shop bought fertilizer will have a different NPK ratio. You can choose the right one depending on your specific plants needs. This goes for both indoor and outdoor plants.
The clues to look out for:
Yellowed leaves (old growth) – Indicates a nitrogen deficiency.
Yellow-edged leaves (old growth) – Indicates a magnesium deficiency.
Warped, misshaped new leaves – Reveals a calcium deficiency.
Purple/reddish leaves – Lack of phosphorus.
Deformed fruits – Typically due to potassium, though nitrogen excess can contribute.
No flowering/dropped flowers – Can point to lack of phosphorus.
Light green foliage (rather than dark green) – An “anemic” appearance could be nitrogen deficiency.
“Burnt” leaf-tip appearance – Points to depletion of phosphorus.
Abnormally dark green old foliage – Another sign of not enough phosphorus.
Dark black or scorched leaf appearance – Potassium deficiency.
Wilted old growth – Potassium deficiency.
STAY WITH ME. NOW IVE BRIEFLY TOLD YOU ABOUT NUTRIENTS, THE FOLLOWING INFORMATION WILL TEACH YOU HOW, WHEN AND WHAT TO FEED YOUR PLANTS.
When to feed houseplants
The best thing to do is not wait for the problems above to indicate that your plant is lacking nutrients but to be proactive and feed on a schedule according to their growth cycle to ensure your plant stays healthy and thriving. A healthy house plants needs a regular and rich nutritious diet of minerals to grow and flourish, just like us really. Being a responsible plant parent is to anticipate the plants needs and act accordingly. You can always adjust the ratio of NPK if any of the above issues present themselves.
Spring:
Start feeding houseplants as the temperatures begin to rise and new growth begins to show itself. When the days begin to lengthen noticeably and houseplants shift from a semi-dormant state into a period of active growth then you are good to go. The first three applications should be made at half the recommended strength.
Summer:
When summer arrives, it’s time to switch to a more regular houseplant feeding schedule. How often you feed your house plants in summer depends on the type of fertiliser you’re using.
1. Liquid fertilisers are applied more frequently, bi-weekly or monthly, for example.
2. Granular products are used less frequently, perhaps once every month or two.
3. Slow-releasing houseplant fertilisers break down slowly and release their nutrients in small amounts, over a longer period of time. A single application of most of these products lasts for three to four months.
Autumn:
About 8 weeks before your first expected autumn frost, start reducing your houseplant fertiliser amounts and frequency. Many people do feed during the Autumn, but as the nights draw in and the temperature changes your houseplants will struggle to utilise the feed you are giving them and this can cause further problems.
Winter:
None. Houseplants are not in a state of active growth during the winter and therefore should not be fertilised. Feeding house plants when they are dormant can lead to fertiliser burn and brown leaf tips.
What to feed houseplants
You can buy ready made plant fertilisers but it is important you check the label that the formula is suitable for house plants. I recommend a brilliant feed from Natural Grower. Their feed is brilliant for houseplants and is a lovely organic formula which happens to be a by-product of a renewable energy plant. Pretty cool huh?
I always feed organically where possible and generally speaking when feeding indoor plants I use a liquid feed. I do the same for outdoor plants in pots but tend to veer towards a slower releasing fertiliser for outdoor plants in the ground.
TOP TIP
You could even have a go at making your own feed for your plants. This tried and tested method is used in my house every year and is a lovely sustainable and FREE way of feeding.
You can make an excellent house plant feed with garden nettles as they are rich in nutients particularly Nitrogen. Be sure to wear protective clothing and gloves if picking your own nettles and avoid picking near a road or other area where they may have been sprayed with chemicals or interfered with by local dogs!
Quick method: Steep 1 ounce (28 g.) of nettles in 1 cup (240 ml.) of boiling water for 20 minutes to an hour, then strain the leaves and stems out and toss in the compost bin. Dilute the fertilizer 1:10 and it’s ready for use.
However you choose to feed your houseplants it is a journey of trial and error. Over time you will find a method that suits you and makes your plants happy. If you have any questions please do feel free to ask me by emailing or by commenting on this blog post. Remember, there is no such thing as a silly question and If you ask me a publicly, there will be many more wanting to ask the same question.
