Watering your plants correctly is one of the most important factors in keeping them healthy. We frequently get asked how to know when a plant needs watering and how often it should be watered. This is where many people go wrong with plant care, whether they’re a forgetful under-waterer or an over-enthusiastic over-waterer!
There is no “one size fits all” approach to watering plants, like us plants are individuals and have individual needs. So, instead of giving you exact parameters of when to water and how much, we’re going to give you 6 easy tips that you can apply to all plants, to ensure you’re watering them properly. The advice is generalised and applies for all types of potted edible and houseplants. Let's get started with some initial considerations!
What do I need to consider when watering my plants?
There are lots of factors that will influence how often you’ll need to water your plant. These include:
Water demand for that species
Water retentiveness of your potting medium
Light, temperature and humidity of the growing environment
Hanging plants (they dry out quicker)
Dormancy (in winter many plants go into a dormant state, during which they require less water)
So how can I tell when my plants need watering?
1. Pay attention to your plants
The best tip in general plant care is to pay regular attention to your plants! Watering incorrectly is one of the biggest reasons leading to poor plant health and it’s often due to neglect. Our busy lifestyles can make it easy for us to forget to check on our plants. How many of us have had the thought ‘I need to water that later’ and promptly forgotten to do so? Probably quite a few.
Checking your plants every day or two allows you to observe small changes like wilting leaves. Being aware of changes like this will mean you can act preventatively if your plant is drying out and is far more effective than a fixed watering schedule.
2. Research your plant's needs.
When you start growing a new plant (edible or houseplant) you should do a bit of research into its specific plant care requirements. There are hundreds of articles on plant care for different houseplants and edible plants. You can make simple notes to quickly refer to for each plant species.
For example, a simple search for “Prayer Plant plant care” tells me they prefer well-draining soil, which is kept moist but not soggy. For my Prayer Plant, I only let the top inch of soil dry out between watering, this usually takes a week, but can dry out quicker when the temperature is warmer.
Knowing which plants will dry out quicker than others is a great way to be on top of your watering routine. Remember to check plants in warm, dry rooms regularly, as well as those in hanging baskets as they will dry out very quickly. When we move into autumn you can reduce watering frequency for most plants because they will not need as much in dormancy.
3. Check the surface of the soil
At a quick glance you can tell if the soil is dry on the surface of your pot. Moist soil is almost always darker than dry soil, so when you see lighter brown coloured soil this indicates surface dryness.
While this technique gives a general indication of plant dryness, it’s best suited for plants that can be kept moist all of the time, such as Umbrella Palms and Boston Ferns.
It isn’t so useful for drought tolerant plants like Cacti, Succulents and Ficus species; watering these when only the surface is dry will inevitably lead to overwatering. For these plants you need to delve a bit deeper to know if they need watering.
4. Poke your finger into the soil
One of the easiest ways to check if your plant needs watering is to stick your finger into the soil. This gives you a clearer indication of the soil moisture content than simply looking at the surface. You can reach 2-3in into the soil and feel how moist or dry the soil is. This technique works best for smaller potted plants because of limited reach. Be careful not to damage roots when you try this technique; if you feel roots try another area in the pot.
5. Lift your pots to determine their weight
Another way to tell if your plants need watering is to lift their pots to determine their weight. This is a common practice in nurseries when watering.
If the plant is dry it will be lighter than usual, as water adds to its weight. This is a really quick method and is recommended if you have lots of potted plants! For larger pots, try to tilt them to gauge their weight.
You’ll get better at this technique the more you try it. By regularly picking up your potted plants you’ll know when individual ones need watering. Once you finish watering, lift the pot so you get an idea of its heaviest weight. This makes it easier to compare its weight after a few days. If it feels a lot lighter, chances are it needs watering!
6. Use a moisture sensor
Practicing all the techniques above will certainly put you in a good position to know when to water your plants. However, there is no reason to neglect a good technological solution, especially when you can usually find them for less than £10.
You can use a moisture sensor by placing the probe about ¾ of the way into the potting medium. Moisture levels will be shown on a dial, sometimes indicated by colour, with red (soil is dry), green (good moisture level), blue (soil is too wet).
So there it is, six simple tips to help you determine when to water your plants. If you follow this advice you'll soon be a pro with the most important part of your plant care routine!
Remember to do some research on the water needs of your new plant because all plants have different tolerances to moist soil. You'll be able to tell if your plant needs watering by observing the dryness of the soil surface, as well more accurate techniques like poking your finger in the soil and picking pots up to determine their weight. You can also use a moisture sensor to quickly and accurately check soil moisture levels.
The most important thing to remember is to pay regular attention to your plants, it just takes a few seconds every day to make sure they are healthy and being watered properly!
I hope you found these tips helpful, feel free to get in touch if you have any home growing conundrums, we're here to help! (contact details below)
Square Mile Farms bring vertical, urban farming to city dwellers in their homes and in the workplace. We aim to bring people closer to food production and help to create a culture of healthy, sustainable living. Find out more about our offering and get in touch here with any queries. Sign up to our newsletter for tips on a healthy lifestyle and a round-up of relevant news. You can also follow us on social media to stay up to date with our journey, find us on Instagram, Twitter and Facebook. Why not join our online Urban Growing Community for advice on growing at home and much more!