I know many new (and old) plant parents have a hard time determining when to water and more perplexing to them is how much to water to give their plants. I want to talk about how to make sure your plants are thoroughly watered. How do you know?
The Dark Ages
I remember when I first started growing plants (back in the dark ages) and I had succulents and cacti and because I knew they stored water, I gave them tiny “sips” of water so I didn’t “overwater” my plants. The crested euphorbia below is one of the plants I am referencing and it is over 30 years old.
The wrong way to water
Watering a plant with little “sips” of water is the wrong way to water. I did that for years and the plant really never grew much. I was in a garden club and attended a flower show where the cactus and succulent society had a display. They had a euphorbia like mine and it was huge. I asked about my small plant and I was told it needed more water than I was giving it. The man told me a cactus needs to be watered the same as any other plant, just not as often. My plant grew in leaps and bounds after I stopped giving it tiny sips of water and started watering it thoroughly. It should probably be a lot larger but I keep it in limbo for years by barely watering it.
The right way to water
The way to thoroughly water a plant is to water it until water runs out the drainage hole and water the entire soil surface so that the whole root ball is moistened. This brings me to another point. If your container does not have a drainage hole, it is best if you drill one.
If you decide not to drill a hole in your container, use it as a cachepot (French for “hide a pot’). Keep your plant in its grower’s pot, place it in the pot without the hole, take it out to water, drain, and return. I don’t recommend direct planting into a pot without a hole. And NO, putting pebbles or other “drainage” material in the bottom of the pot is NOT necessary and does not work.
Plants that had no drainage holes
I’m going to show you two examples of plants that suffered and both are now dead because they were in pots without drainage holes and they were given more water than the plants could use. Because the water had nowhere to go as it had no hole to escape out of, the oxygen spaces between the potting medium particles were filled with water. Roots need oxygen to survive and the water pushed it all out. The roots rotted, and the plant had no way of getting water any longer. Often plants look like they need water because they are drooping and actually, the plant IS dry because their roots have rotted and they can no longer take up water. The root ball is wet, but the plant is dry. Make sense?
This Thanksgiving cactus was brought to our garden center by an older gentleman that knew he had probably given it too much water in a container that had no drainage hole. He was hoping I could help. The leaves are wrinkled, appearing as if they need water, which they do, but there are no roots left to provide water to the plant. I took some cuttings and maybe they will revive and grow new roots, but I doubt it.
He didn’t want to drill a hole in the pot because “Where would the water go? I don’t want it to get all over.” A drainage hole and a saucer underneath to catch the excess water would have been best. Now he has no plant……
Watering larger potted plants
When you check the water needs of a small potted plant 4-8″, using your finger or lifting it to check the weight is usually sufficient to determine whether it needs water or not. But when deciding whether to water a plant that is in a larger pot 10″ and above, it may be hard to tell. Often if you were to put your finger in the soil to check for moisture in a large planter, you may determine it needs water. Yet, what is happening in the top few inches of the medium may not be what is happening in the bottom area of the container. It may be moist at the bottom of the root ball and drier at the top. The best way to find out is to insert a dowel to the bottom of the pot and let it stay there for a minute or two. Pull it out and check the end for moisture. If the dowel is moist, it would be better to put off watering for a few days. If it is dry, give it a thorough watering, meaning until it runs out of the drainage hole, making sure to water all the way around the top of the pot so the entire root ball is moistened. If you only ever water a plant on one side of the container, the side not getting watered may have root damage. Add water slowly to allow time for it to run through the entire root ball and not fill the saucer to overflowing.
Excess Water Removal
If after you water, the excess water has collected in the saucer, and approximately 30 minutes to an hour later, there is still water in the saucer, it is time to remove it. If you can’t move the plant as it is too large, a turkey baster works great to remove the excess. You do not want your plant standing in water for too long, or that dreaded root rot will begin.
I hope this all made sense to you. Watering your plant thoroughly every time you water is important. It doesn’t matter if it is a cactus or succulent or a fern or a peace lily. Water until it runs out the drainage hole. The key is when you water your plant again. A cactus or succulent may not need water for weeks, whereas the fern and peace lily most likely will need water again the next week. Never water on a schedule, but check your plants often for their watering needs.
Have a great week, plant friends!