My number 1 rule has always been to make sure your patio pots and container gardens for plants have sufficient drainage. There is no doubt plants perform much, much better when they have sufficient drainage holes in the base of their pots. Oxygen is necessary for plant roots to develop and perform better, and without drain holes, they lack it.
But, what about all those good and unique pot finds with no drain holes which you want to plant your succulents in? Vintage tea cups or a cool rock? Or when you are growing plants in hanging glass globes or in glass terrarium bowls? How do you deal with the fact these types of pots have no drain holes. If you cannot drill them, which is tricky with glass in particular, then the answer is to water very carefully.
Because succulents are able to withstand periods of drought, many people use them in pots without drain holes, but they do need watering at some point. In fact, succulents tend to like a good drenching, and then you should allow the soil in the pot to completely dry before you water again. The key is watering carefully when you have no drain holes.
Here is a list of tips I created to help you do this correctly, and again, carefully.
Tip No. 1 – Use Sphagnum Moss
Add some moss in glass hanging votives or glass globes over the soil mix. Fibered sphagnum moss absorbs up to twenty times its weight in water. The moisture will distribute naturally throughout the moss reaching the plants’ roots. The moss will dry over the course of the next few days on its own. By the way, sphagnum moss is not peat moss. And, Spanish moss is also different. Spanish moss is more for decorative uses and will remain soggy longer than sphagnum moss. I prefer the sphagnum moss because it dries between the moisture routines allowing the aeration also needed for the succulents delicate roots.
Tip No. 2 – Tip the pot
After putting water in the soil mix (or moss), tip the pot to drain out any excess water, especially if you over did it. It may be okay to let the water sit there for a bit to be soaked up awhile, maybe an hour or so, but then be sure to drain out any excess water from the globe, pot, or whatever has no drain hole.
Tip No. 3 – Unplug the weep hole
Some pots, such as this hanging basket, has a reservoir area in the base. If the pot got overfilled with rain water during a heavy rain fall, pull the plug out, and allow the accumulated water to drain completely out. After, let the soil dry out and then re-insert the plug.
Tip No. 4 – Add horticulture charcoal
Charcoal is very useful in terrarium glass bowls in particular. It improves drainage and absorbs harmful impurities. Add a thin layer in the foundation of the bowl along with soil and gravel in the base. It may be used in pots without drain holes too if desired. It will help the soil environment. Just be sure to follow the guidelines on the bag for the amount to use, and wear gloves since it is a messy dusty like component which will blacken your hands. Layer it appropriately as well for terrariums.
Tip No. 5 – Less is more
Do not over water especially if your pot is in a dimly lit room inside your home or in the shade outdoors. This is a formula for inviting fungus gnats. The moisture will not dry out as quickly in shady spots, and thus, it invites critters. Critters like moisture. Be aware less is more in these situations, but again, your succulents shouldn’t be in non-lit areas in the first place. Most succulents prefer sun. If possible, if the soil is too wet from this situation, put it outdoors on nice days to give it natural air. Just be sure it is warm enough outside and not in too much sun IF the plants have been inside all winter. Select a partial sunny place and bring it back in later before evening.
Tip No. 6 – Use a porous pot
Terra-cotta and non-glazed clay pots allow air movement through the pot itself, so using a clay pots helps the non-drain holes situation versus using a glazed ceramic pot for example. Also, fabric or fiber pots with the natural ability to allow moisture to seep thru the pot base, are helpful to use. Such as coco fiber liners used in hanging baskets.
Tip No. 7 – Add perlite
Your potting mix may already have perlite, but adding more to the soil mix for pots with no drain holes will enhance the air spaces in the soil. Horticulture perlite is expanded volcanic glass. It increases aeration and drainage which will help the roots develop. This tip is good for plants which enjoy lots of drainage, such as succulents. Perlite is available by the bag in garden type stores.
Tip No. 8 – Create a drainage layer
Add gravel, stone chips, sterilized sea shells, or river pea gravel to the base of the pot before adding the soil and or moss. This is only recommended for pots without drain holes. Otherwise, if the pot does have drain holes, it can be counterproductive, creating blockage to drain holes or moving up the soil moisture above the gravel line. More on that in another blog post. It is a bit of a thing to explain to folks, which I have in my workshops on container gardening in the past.
Tip No. 9 – Allow drying time
Most plant roots need a balance of moisture and air. Be sure to allow your soil to dry between watering, especially important when you have no drain holes and are using succulent plants. Succulent plants should not be sitting in soggy soils for prolonged periods of time. And if the weather is right, put your container outdoors for some fresh air to give some air to the soil or moss, just be careful to not put it in harsh sun right away if they’ve been indoors all winter. And do not put out non-hardy soft succulents outdoors if it is still cold out – usually the right time to transition them outdoors is around Memorial Day, but if there is a suddenly warm day and sunshine, it doesn’t hurt to put them out for a few hours if the soil is really too wet.
Tip No. 10 – Direct the water
Direct the water carefully to the soil mix (not to the top of the plants). Do not mist succulents. Point the tip of your watering-can spout to the soil, moss, or around the plant. I’ve been using a hair style water bottle lately for succulents in tight pots. The bottle is squeezable and squirts out a stream of water perfectly from a very narrow tip. If your succulents are a hardy type, and outdoors, it is okay if they get wet especially in the sun, but for soft non-hardy succulents, it is best to avoid getting the foliage wet. Also, bear in mind, newly planted succulents may have not expanded their fine roots into the soil much so the amount of water may depend on if you just planted a plug or baby succ, versus one that may be fuller and more mature.
And finally, I think this goes without saying, use a quality potting mix or container mix for your plants in the pots. No native soil, no dirt please. In a future blog post, I will talk about my favorite potting mixes and how to find them. I have my favorite brands, and I actually listened to a webinar yesterday on new wood substrate type components for peat-based potting mixes. Again, more on that later. There is always more to learn.
Thank you for visiting.
Owner of Container Crazy CT
Broad Brook, CT