Several years ago, I came up with what I called, “The 5 Must Do’s for Successful Container Gardening” to help attendees of my workshops succeed with their patio pots and container gardens in the summer. Most of what was written then still holds true today, but some things have changed. I am going to update my “5 Must Do’s” in a series of articles on this blog. To get started, here’s a review with some 2019 updates:
For Successful Container Gardening
- Provide additional drainage holes in the base of your pots – Still True! And still a number one rule!
- Use soilless potting mix specifically formulated for container gardening – Yes, but there are soooo many more choices today – it is sometimes overwhelming to know which bag of mix to select. How do you know which to pick? I will go over this in an upcoming article here on this blog.
- Add slow release fertilizer to the soil upon planting – Still a trusted method for me but there are many other choices today of various fertilizers. This is a topic to be updated with more suggestions.
- Water your plants on a routine schedule – There is no doubt – this follows rule no. 1 in regards to importance. However, some plants are more drought tolerant than others – so if you are bad about watering, I am going to make suggestions for you on your plant choices. And a ‘routine schedule’ is probably not the best wording – it is really all about how the soil is looking in regards to a balance of moisture and air – we will go into details!
- Use big pots to increase your growing power – Guess what? I’ve changed my mind on some of this – I still adore HUGE tropical plants and mixes of annuals or perennials in big pots – but some plants actually prefer smaller pots and I will be offering a blog update on this number 5 rule as to why. Using big pots is not always a rule, and is optional…
Let’s get started:
It may seem straight forward or common sense to do the five items listed above, but many people skip some of these steps when they assemble their container gardens and patio pots because they are either in a hurry, want to avoid spending extra money, or they don’t understand the negative impacts to the plants’ overall health and appearance when they don’t follow The 5 Must Do’s listed above. But, do these 5 important steps and you will achieve successful container gardening status every time.
DRAINAGE – Must #1
Most pots on the market today have only one small drain hole in the base (or none at all) – and this is not sufficient. If the soil in the pot remains too wet, the plants’ roots will not get the oxygen it needs. And oxygen is required, along with carbon and hydrogen, for plants to grow. Having constant wet soil in the base of a pot is similar to walking around in wet sneakers. While it may be tolerated for a short period, if air is not provided soon, rot or death may set in. Everything above the pot is depending on what is going below in the soil, so Must #1, providing additional drainage, will allow for the free movement of water throughout the soil profile which is extremely important because as those spaces filled with water are vacated, air can replace them for the plants’ roots to use oxygen.
Without sufficient drainage, your plants will not perform as well which leads to failure. It is a step you should not forgo or skip, and must do in order to achieve beautiful plants in your container gardens and patio pots. Once you see the difference in your plants health, you will find adding drain holes so valuable, you will never skip this step again. And, although specific potting mixes have ingredients to help create pore spaces for air, adding more drain holes to the base of your pots only enhances the soil environment for your plants. It leads to ultimate success because the roots are thriving in a healthy soil environment which is well-drained and balanced.
So get your power drill out and use a drill bit to create holes about the size of a quarter (coin) in the base of the pots. Be sure to drill at least 5 or 6 holes evenly spaced apart (one in the center and a few around the diameter). If the pot cannot be drilled (e.g., ceramic or clay), make sure it has at least one drain hole already built into the base by the manufacturer, or reserve that pot for plastic plants or water gardening. Do not use pots with no drainage capability. This always leads to poor results, trust me (except if you are creating a water pot garden).
One of my biggest frustrations with the market place is they still continue to offer pots with no drain holes. What are they thinking? Plants require drainage! I have posted this comment on Instagram – “Hey, pot makers – Please make pots with sufficient drain holes please!”
If they did this, we would not have to drill them ourselves and it would help sell their pots because the plants would do better in them. It is not to say I haven’t seen some with drain holes in some stores, but it is progressing slowly and not common. I wish they would offer more with them already pre-drilled for us. (Hint to pottery makers, same for those wonderful pots you make – make some with a drain hole please.)
In my container gardening workshops, I have held up grower pots – the ones you buy your plants in – to my audience. I tell everyone, take a look at the bottom – what do you see? SEVERAL, I mean SEVERAL all around drain holes. Growers know what they are doing. It is a good example to show how important drainage holes are in your pots – this holds true for growing seeds in seedling cell trays as well. Or when you put a succulent in a pot – many times, you will see pots for succulents with no drain holes – succulents can be an exception to the drainage rule due to their ability to go without water for weeks at a time, but you have to monitor your watering carefully with succulents in pots with no drain holes. That is a whole other topic to explain, which I hope to do soon, and will in my Succulent Hanging Baskets Workshops in May, where we will be designing them with an amazing array of succulents of all kinds. But that is for a session/class, and for now, we want to focus on the drainage needs of container gardens and patio pots in general.
Over-watering is a leading cause of plant issues for people who are new to container gardening and plants. When you over water and the soil stays too wet in a pot, well, as mentioned above, the roots will rot. But other issues surface when there is too much moisture.
One, for example, is you may get fungus gnats showing up – they need moisture in the soil to thrive. This is especially common in houseplants where people have them in pots inside their home. And sometimes, you may even see mold on your soil when it is too moist. Moisture (with a lack of air circulation) may cause big problems in your soil. Too much moisture in your seedling pots leads to damping off. Water is a requirement for plants to grow but if over done without proper drainage, it leads to issues at times.
Balancing the air and moisture in your container gardens and patio pots or home pots of any size is critical. And soon, I will write a blog post to expand upon the air and moisture of pots as part of the 5 Must Do’s series updates I plan to post here on this blog, Container Crazy CT over the course of the next few months. In the meantime, be sure to add drain holes to plastic pots or buy pots with holes in them already for the best success with your plants.
SOILLESS POTTING MIX – Must #2
Soil (dirt) from the ground cannot be used as a substitute for potting mix when planting up your patio pots and container gardens. Must #2 is you must use soilless mix specifically formulated for container gardening. I know what you are thinking, if plants can grow in the ground, why can I just dig up some dirt and use that in my pots? Well, for starters, soil from the ground becomes very compact in container gardens. Plus, with container gardening, you have to water more often resulting in the ground soil (dirt) becoming even more compact and dense in the pot as it compresses down in limited space. Young new roots cannot grow through this and cannot get the oxygen or water they need.
To prove this point, I put ground soil (dirt) into a mason jar and soil from potting mix into another mason jar. The weight difference between the two jars was substantial. The dirt jar weighed about two pounds and was very heavy. The mason jar containing potting mix was light as a feather. Imagine roots trying to penetrate the heavy compacted poor soil, plus it won’t contain the balanced nutrients or air spaces for the roots to thrive and survive. Roots are just as important as the top part of the plant – if not more important. Everything below the soil impacts the results above the soil.
Additionally, soil from the ground (dirt) can harbor soil borne pathogens, insects, and weed seeds – and you don’t want those in your container gardens. The ground soil may be too hard (clay) or too porous (sand). Soil in container gardens must have good pore structure for root growth, water holding for even distribution, and oxygen for the roots, and of course, nutrients for the plants to grow healthy and strong. Soil from the ground will not give these must needed elements to plants in container gardens. And trying to find the ideal ground soil that has all of these factors is a big chore, if not impossible.
Bottom line: Do not use Dirt. Dirt is a four-letter word in the world of container gardening.
Most potting mixes on the market contain a combination of bark, wood fiber, coir (a by-product of coconut husks) or peat, vermiculite, perlite, and maybe some compost. The little white non-symmetrical round things you see in the soil is called perlite. These provide pore (air) spaces in the soil required for roots to grow. Other ingredients mentioned help with water retention (peat moss, coir), drainage (pine bark, perlite, rice hulls), and nutrients (compost). You want a balanced soil that can hold 25% air, 25% water, and the rest, 50%, is organic matter. Plants must have the appropriate pore space, water holding capacity, and nutrients to grow. This is especially critical in container gardens because roots are confined, cannot extend out to find its needs elsewhere, and they depend on their current environment and “you” to grow well.
When planting up your container gardens and patio pots, go out there and invest in a couple bags of potting mix specifically formulated for container gardening. The good news is there are many types available today, and by the way, none of the potting mixes used for container gardening contain any real soil (dirt) at all. Now you know why, it is should no longer be a surprise to hear this. Once you start using potting mix, you will be pleased to see how well your plants are growing and thriving. There are tricks to extend your potting mix life, but that is another topic to be posted later.
Now that you know you should NOT use “dirt” in your container gardens or patio pots, the big question is which potting mix should I buy? It is OVERWHELMING because today, the market place has many types to choose from – and you stand there looking at all the bags scratching your head thinking, which is the “right” one? I want to succeed, and I read Cathy T’s 5 Must Do’s, but I’m now afraid to pick the wrong one.
I will be posting about my favorites, but one big tip is inspect the bags. Picking up a bag of soilless potting mix (and by the way, it is not labeled soilless, that is just a term used, it is usually labeled as “potting mix”) is similar to picking out produce in the grocery store. Look at the bag’s condition, especially if you are shopping at a low-end type store. Is the bag torn, heavy, wet and a mess? Hmmm, that is like a banana or avocado about to rot, in my opinion. It could have been an older bag, and the soil in there may be even worn out – unable to take up moisture. Be careful with “deals.”
Check the weight of the potting mix bag. Is it light and airy feeling? GOOD! Is it rock hard, wet and very heavy, hmmm, not so good. That is not to say it is bad because some bags are out in the cold early in the season, and may be thawing out – but I always go for the ones that look fresh and are in good condition. The weight of the bag gives you clues.
Go to a reputable nursery, see where their soil is placed outdoors – businesses who put their bags of potting mix under cover – with a roof top of sorts – are a winner in my book. Or if they are a popular and reputable nursery, they have lots of FRESH soil bags put out there early in spring especially. They also have staff available to answer any questions you may have if you find there are lots of choices. Be observant. You can tell who is on top of their game, if you just pay attention.
As for the big box stores, some of the mixes are good, but some I am weary of. I will be writing more about the products I like and I share all of that in my May container gardening workshops in detail. Heck, we even test soils in some of my sessions, like I did recently with “seedling mixes” in my recent Seed Starting Session. Horticulture and growing plants is a science and an art. You may have a mix you have found to be wonderful, or maybe you have been using a mix causing problems which are not YOUR fault – it is the mix (and you didn’t know it). We go over all of this in my workshops and sessions. Making your own mix is another option which I plan to go over as well, but some mixes are so excellent and it just saves time to get the pre-made mixes.
Lastly, the type of plants matter. Cactus, succulents, and houseplants have different soil needs compared to tropical plants, annuals, and perennials growing in mixed container gardens. For example, succulents and cacti appreciate more drainage and air space in the mix.
And lastly, I saw a new product on the market recently to help refresh older mixes in your pots – which I will be testing this year myself to see what I think. Heck, there are signs of people growing plants in no mix at all now – using special beads or growing in water. The learning never ends. I always test out new processes first before offering my take on them.
SLOW-RELEASE FERTILIZER – Must #3
Once you have your drainage holes and soilless potting mix in your pot, you want to add slow release fertilizer to the soil to obtain optimum growth. Slow release fertilizer will provide small amounts of nutrients to the plants’ roots over a specific period of time. While some potting mixes come pre-charged with fertilizer (meaning they add the fertilizer in the mix as an ingredient), it may not be substantial enough to keep your plants fed throughout your container gardening season. Add some when you get started, and don’t have to think about it again unless you are dealing with a high demanding plant or you didn’t follow the rest of The 5 Must Do’s.
Many slow-release fertilizers on the market are available in a granular form which is easy to apply. The little round balls you see in the granular fertilizer bottles or bags are called prills. Each contains a balanced release of NPK (Nitrogen, Phosphorus and Potassium – the three macro-nutrients needed most by plants). Nitrogen promotes leaf, stem, and above ground growth. Phosphorous promotes rooting, flowering, and fruiting. And potassium helps with disease prevention and cold tolerance. If you put too much of any, you can burn the plants or even kill them. However, the nutrients in the prills of slow-release fertilizers will slowly leak out into the soil as water vapor is absorbed into the prill through its coating. It dissolves the fertilizer inside to feed your plants during your container gardening growing season – which is typically 3 to 4 months in Connecticut, from May to September. As the soil temperature warms (during the summer months when you want your plants to thrive the most and when they need more nutrients during their most active growth period), the nutrients are released even more when the prills’ coating expands as a reaction to the warmth in the soil. Think of the slow-release fertilizer feeding as a well-balanced diet for your plants to stay healthy and beautiful. It will be handled for you in a controlled manner.
Add the slow release fertilizer upon planting your container gardens to ensure a continuous feeding routine. Do this one simple step, and you will be amazed at the results. And it also eliminates the needs to add water soluble fertilizer as a supplement later in the season, especially, as I said, if you follow all five of The 5 Must Do’s.
One of the biggest ongoing trends or change in gardening is the love of organics, and this is a good thing. Some slow release fertilizer are synthetic while others are organic based. I go over these in my workshops and their differences, but I still think slow-release fertilizer of either type work very well and are EASY to apply and you don’t end up burning your plants. I still use the trusted brands of slow-release fertilizers I’ve always loved and always add slow released fertilizer to almost all my container gardens and patio pots. It just works. Again, some mixes come pre-charged with starter fertilizer but adding the slow-release prills gives the plants a balanced diet over the course of 3-4 months and now many last 5-10 months! The coating size of the prills varies and this is what makes it last longer than others – look at the bottle’s instructions and follow accordingly.
However, I’m on several plant related Facebook groups where there are tons of questions asked, and many times, the subject of fertilizers come up. Wow, the brands some people show and have used, I have never seen before (because the members of these groups are from all over the world). Again, almost like the potting mix choices, it is confusing at times, which should I use? Which is safe? How do I use it? When do I use it? We go over specifics in my workshops based on the plant types.
I read once a nursery owner saying, everyone has different methods of gardening – and this is true – some go into it blindly however, and the 5 Must Do’s are here to get you started, but what I’d like to do is dive into the fertilizer topic more as part of my series of the 5 Must Do’s.
Also, I always always tell my attendees, if you follow the 5 Must Do’s – you don’t have to fertilize as often. I believe over-fertilization advice is given at times. If you have a healthy growing environment with the soilless potting mix and drainage, you are off to a good start and may not need much supplemental fertilizing as the season progresses in summer.
WATERING – Must #4
Forget container gardening if you are not willing to water your plants in container gardens and patio pots. Must #4 is all about giving your plants watering love and it must be done on some kind of routine basis and based on the plant type and your environmental conditions (sun, shade, inside, outside, summer, winter, etc), but it must not be skipped or completely forgotten. Watering in the morning is helpful because the plants take up the moisture during the day while photosynthesis takes place. If you can’t do it then, please do it when you get home after work. A plant will remain strong as long as the movement of water through the soil is in balance. And you are that balance. Without watering, your plants are doomed. If they don’t get water, there is no growth, and stomates in the leaves will close up to prevent further water loss to protect themselves. Then, the plant will wilt and it certainly won’t flourish. If no watering occurs for an extended period of time, the plant may reach a permanent wilting point and never recover. And you don’t want that after you invested in buying beautiful plants from the nursery or from Cathy T (me!) to enjoy and show off at your home.
If you are not sure if the plants in your container gardens needs water, look at the plants – Are they wilting? Do they look thirsty? Or insert your finger into the soil at a two to three inches depth. Does it feel damp or sufficiently moist? It may be okay. But you absolutely cannot forgo watering your container gardens. Even if it rains occasionally, or you used drought tolerant plants, you must pay attention to them and their needs in regards to watering. Observe the plants’ overall health, get familiar with their watering needs, and pay attention. Climate in your area, the type of material from which the pot is made, and location will dictate some of the timing of your watering routine, but it is not the only factors you should pay attention to. Basically YOU need to pay attention to watering.
Some people think they can douse their container garden plants with lots of water all at once, walk away, and forget about it for a week or more. This does not work. The soil needs periods where it dries out a bit between watering too. It should drain (Must #1) and have some breathing room (Must #2). You don’t want to overdo it either, where the soil remains too wet. Wilt can be a result of over-watering as well as under watering.
Watering is one of the more difficult of The 5 Must Do’s to master because every plant and container type is different. And because people’s habits are different. And the weather and exposure will affect how much or how little water your plants will need. There are some tricks to help reducing your watering routine, but that is another post for another time. Bottom line, you MUST WATER your plants or they will die. Plants need water to live. In fact, every living thing on this earth needs water. We need water. Without it – we all die. If you will not water, you should not do container gardening. In my opinion, not watering your plants is like committing plant murder.
As I read my information above on watering (written several years ago), I think, yes, this is all still true in 2019. Watering, I think has been my biggest challenge to convey to attendees – is there a simple rule when it comes to watering? The answer is no. But – there is an observation factor involved in watering. You need to think about the soil. When you last watered, and all of that above. You really should NOT just think, “Hmmm, I’ll water every Friday and put one gallon in that big pot.” It really doesn’t work that way, there is a BALANCING act involved. But then, we don’t want to complicate watering, do we? The key point is that you must accept you need to water your container gardens, especially as we venture into summer, or you will not succeed, and your plants will suffer and look unhappy. I guess you could say, well, watering is like doing your physical exercise, you need to keep it consistent to have the plants and you do their best.
There have been times I wanted to do a watering type demonstration – using a shot glass, coffee cup, beer mug or wine glass, and milk jug to show the amount of water to be used based on the size of the pot and the plant type. Maybe I will get around to demonstrating this – but think of this: shot glass (succ), coffee up or wine glass (houseplant), beer mug (hanging basket), and milk jug or jugs (big veggie pots) – get the idea? But it also has to do with how moist the soil is, and did you let it dry somewhat to give some of that air space between waterings, and the type of plant. And yes of course, where your pot is situated. Outdoors in full sun, inside on a window sill, or in the shade. All are factors.
BIG POTS – Must #5
People fear buying big pots, probably due to concerns with cost, placement, and moving them. But big pots and container gardens make a big statement! They capture your attention, create a focal point worth noticing, elevate the arrangement of your showy healthy plants, and ultimately reduce the compaction problems of small pots – so movement of water in the soil is enhanced. Big pots also provide good anchorage of your large plants, hold more inches of water, don’t drain out as fast which helps to reducing Must #4 (but not eliminating that must), and enables you to grow larger, showier plants – leading to more bang for the buck. Go for supersized if you can.
However, with that said, big pots is listed last on The 5 Must Do’s list because it is not mandatory for success, but using them will elevate you to a higher level of container gardening. My recommendation is you should invest in at least one big pot. Just one. I believe you will never regret it. It makes a tremendous difference to the plants’ performance when you give the roots a large mass to grow in. Also, as noted above, using big pots make a big statement in your outdoor environment. So why not make your container gardening show magnificent for the season?
There are some tricks to helping with the amount of soilless potting mix you have to use to fill up a big pot, but that is for another post. Big pots may be a little challenging to move or fill, but place them in the right spot before you get started, and go back to Must #1 through Must #4 to get them in the best shape ever, and then wow yourself, your family, and your guests as they visit you to see your amazing and stunning container gardens. You will feel a huge admiration for your efforts, a new appreciation for the world of container gardening because you followed The 5 Must Do’s, and your plants will love you for it too.
Okay – Okay – I know – maybe not as big as my cement planter shown above in the photo – that is one monster pot! And I love it to this day for showing off my amazing tropical plants grown every year from overwintering tubers, rhizomes, and corms, etc. However, what I meant when I wrote the above is when we did many of my May workshops with a mix of tropical plants (banana, canna lily, elephants ears), and big pots really made the show spectacular. In those days, I would recommend attendees bring a pot about 22″ in diameter and at least as deep for those types of mixed container gardens. Boy, did we ever have fun getting those big pots into their vehicles when they left the day of the workshops.
But, alas, times have changed. Succulents grew in popularity and still are very popular – that trend continues. My joke on that is succulent growers must be dancing in their boots about the passion of succulents these days. They are wildly popular, and guess what – most succulents do not need BIG pots. In fact, they have such shallow root systems, they do just fine in wider and less deep of pots.
And house plants for that matter should not be moved up into a bigger pot too quickly. Their roots tend to grow slower and thus if you move them up into too big of a pot, the roots may rot – because they are not taking up that moisture as quickly, and the soil could remain too damp, so it is recommended to move houseplants into one size up higher pots when they become root bound or over grown, etc.
But when it comes to vegetables, like tomato and pepper plants, well, big pots are recommended and needed, and I talked about this in my seed sessions recently – we went over types and size of plastic pots and fabric grow bags for growing some veggies. Some require the number #5 rule of big pots. But herbs, well, they are fine in smaller pots and in hanging baskets, etc. And radishes or carrot require different size pots too. Lettuces do well in window boxes. You get the idea.
Thus, plant types dictate the pot sizes, so the #5 rule is really optional and based on plant types you are using to make your beautiful container gardens for the season. It is not really a hard rule.
As I provide this Quick Update to my 5 Must Do’s, I remembered, I had a rule no. 6 to add. Now, for the life if me, I’m sitting here thinking, what the heck was the number 6 rule that I wanted to add? I know it will come to me. In the meantime, hopefully, these quick reminders of the 5 Must Do’s are helpful along with my quick 2019 updates as we get closer to the outdoor planting, decorating, and growing season. As noted above, I plan to do a series in detail of several updates on these topics.
The Five Must Do’s are all about achieving successful container gardens and patio pots. Do all of them, and you will be happy, if not overjoyed, with your amazing results – I guarantee it.
In fact, as a 2019 update, I want to note that I’m amazed by the progress of my attendees’ patio pot creations since they have become fans of my workshops – their results are so good now – they follow the 5 Must Do’s and continue to learn right along with me. I’m very appreciative of the experiences we have had and continue to have learning about the love of container gardening.
Written and Updated by Cathy Testa
Owner of Cathy T’s Landscape Designs and Container Crazy CT
Location: Broad Brook, CT