10 Things You Should Know About Containers (But Probably Don’t)

I love my container plantings.   When I was younger, I use to drag my whole garden around with me from apartment to apartment in containers. These days, I have greatly pared down my container collection, but I still have several that I maintain year-round or plant new every year. Some of my container plants are now 15 years old, and like my teenage children, I often look at them and marvel at the thought that I can still remember when they were no more than little sprouts.   When did they get so big and beautiful?

Because I have grown plants in containers for so long, I have learned a thing or ten about growing plants in containers. Some of these things I have frequently found that many gardeners, even experienced ones, do not know about growing plants in containers. So, as an educational effort and my good deed for the week, I present to you 10 Things You Should Know About Container Gardening (But Probably Don’t).

1. They need water daily, or even twice daily – This one is probably the biggest surprise to people. With our indoor plants, you likely water weekly (or even less). But outdoor plants, the lose water much faster than their indoor equivalents. If temps are below 85F, you need to water daily. Above 85F, you should be doing it twice a day. And, bonus, best time to water is in the early morning. If you are on a 2X a day schedule, than once in the morning and once in the evening.

2. You don’t use soil in containers – And this one always leaves people looking at me like I am crazy. If you don’t plant in soil, what the hell are you suppose to plant in? Answer: Not soil. Soil is defined as containing small bits of minerals in it. Those minerals like to get cozy with one another over time and this happens very quickly in a container, which results in the first stage of rocks developing. Plants don’t grow well in a rock.   You need to use a potting mix, which contains things like peat moss, coir peat or compost.

3. If you let a container dry out, you need to soak it – So let’s say you went on a trip, or you just forgot to water for a day (or seven). You can’t just sprinkle water on your container and expect it to be watered. Most potting mixes, while necessary to a good container planting, start to actually repel water if they dry out.   So when you go to water it, the water just runs uselessly down the sides. If your container dries out, for whatever reason, you need to give that container a long (like 20 minutes to an hour) spa-like soak in a tub of water.   This will force it to get over its hydrophobia.

4. They need to be fertilized – I don’t care if you bought the fanciest, most expensive potting mix out there which comes complete with 29 essential vitamins and minerals needed for optimal plant growth. You still need to fertilize.   With watering daily and the typically crowded conditions of container plants, nutrients either get washed away or sucked up pretty quick. You need a slow release fertilizer at least once a month to keep everyone in the container happy.

5. They need their soil replenished – This is more for the long term container plant.   Potting soils are made of organic materials and organic materials will break down and get washed away over time. So about once a year, top dress your long term containers an inch or so of fresh potting mix.

6. Craft stores are your friend – There are a few things that you can find at craft stores for a fraction of the price of what you would at a garden center. Elegant containers and hanging baskets, spanish moss for lining baskets and adorable garden art can be had at a significant discount.

7. Sometimes they are suppose to be rootbound – Yes, for long term containers, becoming too rootbound is a bad thing. But, if you the container you are planting is only meant to last for the season, pack those suckers in. If you want one of those spectacular looking containers you see in magazines, the secret is to pack the plants in tightly. Yes, they will get rootbound, but they are only going to be there for a couple of months. If you water frequently (refer to #1) and fertilize regularly (refer to #4), your container plants will be happy and look jaw dropping.

8. Mulch is not just for the ground – Containers, especially containers that have plants in the long term, look neater, retain water better and have fewer unwanted, weedy plant guests if you add a layer of mulch to the top of the container.

9. Consider drip irrigation – All of my containers in the front yard are on a timer and drip irrigation.   As mentioned before, I am lazy.   1 hour of work at the beginning of the season and I don’t ever have to remember to water my containers once a day. All you need is a hose, a timer and a drip irrigation set up. If you are just doing a patio/deck/front porch, you can probably set up yourself up for about $50-$75, depending on how many plants you have. I am lucky enough to have an irrigation store near my home, but if you don’t you can easily buy the supplies on eBay. “But Hanna, $50-$75 is alot of money!” Oh knock it off. You know you blow that much at the plant nursery each time you go.   Consider this an investment for your investments. A logically set-up drip system can serve you for years, and save you a fortune in dead plants, time and water.   Plus, you can put plants in hard to reach spots. For example, for years I dreamed of window boxes outside my bedroom windows (which are on the second floor). Guess what, before drip irrigation, everything I planted in those window boxes died because I was too lazy to haul water up to my bedroom every day.   Now I have adorable window boxes with lush plants and I don’t ever have to think about it.

10. Not all plants play nice with each other – When a gardener goes into a nursery, it is a little like a drug user entering a crack house. We can’t walk away without a more few plants. But, if you are planning to put those plants in containers and if you are planning on making those plants be potmates, then you need to pay attention to each plant’s needs. A full sun, drought tolerant plant will have issues if you force it to move in with a part shade, moisture loving plant. One of them will kill the other, and really, plant based death matches are not all that exciting to watch.