I believe that watering is the most important factor in determining whether or not you’ll have success growing plants in a hanging basket. Water them too much and they’ll die. Water them too little and they’ll get crispy and die.
This is true for plants growing in the ground as well (which is why I wrote 5 Rules for Watering Your Garden) but the effects of too little or too much water show up faster in hanging baskets, given the small amount of soil the plants are growing in.
I made a short video to show you two techniques for determining if a hanging basket needs water, and then how much water you should give it:
There is one caveat to all of this, of course, and that is that some plants, like cacti and succulents like their soil to be on the drier side A few plants, like Martha Washington Geraniums (not “regular geraniums”, i.e. zonal pelargoniums), like to be on the consistently moist side. These are the exceptions. Most plants will be very happy if you follow the rules I’ve laid out here.
The two methods I use to figure out if my hanging planters need water are:
My answer to the question of “how much water is enough?” is pretty simple. Add water until water runs out the bottom drainage hole of the planter. The goal is to thoroughly soak the soil, and that’s the best way I know to know that water has permeated the whole planter, and not just the top couple inches of soil.
What to Do If You Forgot to Water and the Plants are Parched
If a hanging basket is completely dried out immerse the whole planter in a bucket of water for five to ten minutes. Plunge it right in. You’ll hear air bubbles coming up and a little bit of the soil may float up as well, but don’t worry about it. After the time is up, remove the planter from the water and sit or hang it in a shady spot to drain. The next day, trim off any of the plant parts that are crispy (“dead is dead” as my gardening mentor says) and continue to grow as normal. Be extra vigilant not to let it dry out like that again, especially not for the first few weeks, as the plants will be in a weakened state.
What to Do If the Plants are Drowning
Maybe you thought the hanging basket had a drainage hole and it didn’t, or the friend plant sitting for you tried to be extra helpful and watered every day–whatever the cause, if plant roots are sitting in wet mud they can’t breathe. Lift the plants out of the mud and get them into a fresh container of potting soil. You can dump the muddy soil out (to be reused later, its not damaged, just wet) and repot the plants into the same hanging basket with fresh potting soil. Or keep them in pots until the hanging basket soil dries out a bit, and then repot them into the original hanging basket. Always make sure any container used for growing plants has a means for water to drain out the bottom.