My Take on Self-Watering Pots

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I have often made the comment during my container gardening workshops and demonstrations that if you don’t like to water, leave this presentation immediately. I actually love to water my container gardens and patio pots. Yes, a bit nuts to hear by some folks, but to me it is relaxing. It allows me to take a moment to enjoy the plants’ features and feel the sun on my shoulders. Not only do I like the whole watering routine, I also realize the importance of water to the plants’ internal functions and growth processes.

Water is the primary component used during photosynthesis when water is split into hydrogen and oxygen by the energy of the sun. Water is also used to transport nutrients, cool the plant, expand its cells, and maintain turgor pressure. And YOU, my container gardening workshop attendees and gardening friends, are the person that will provide water to the soil so our plants’ roots can take up the elements so essential for all this beauty to begin and grow in your container gardens in the summer. Without your watering process, a plant in a container garden and patio pot cannot internally manufacture its own food – a function that only plants can perform on this earth. Sound like a big responsibility? If it is too big for you…well, there are some options.

As shown at my annual May Container Gardening Workshops, there are some tricks used to “reduce” watering routines for your pots needs, but there has also been self-watering pots out there on the market for some time now for people who, UNLIKE me, despise having to water their plants in the summer months. Or, they may not have much time to “relax, enjoy the plants’ features, and feel the environment” due to their busy workday schedules – after all – it does take some time to water container gardens – but its worth it, isn’t it?

As one attendee told me after the summer season was over, watering her plants on her deck felt like a part-time job – but she surely enjoyed the big, lush plants which grew large in her pots all summer. To enjoy your container gardens as focal points throughout your outdoor surroundings is a mental boost to your day. Watering may just force you to stop and take it all in after your work day. It can be a forced relaxation moment in some ways. Now, back to the self-watering pots…

What are Self-Watering Pots?

Self-watering containers and pots have a reservoir of water in the base of the pot. A disk or platform partition is inserted into the pot about 1/3 of the way down with the soil resting above the disk. A fill tube allows you to top off the water as needed which goes below that disk in the base of the pot. Sound easy, huh? Yet, I have to admit, I am not a big fan of self-watering pots, partly because – as I mentioned – I enjoy watering plants, and because there is something about the water ‘not draining’ freely from self-watering pots through the bottom, and through the soil, which disturbs me. After all, do you like the feeling of damp feet when you are wearing shoes that don’t quite breathe correctly?

I don’t think plant roots like that feeling either (damp feet) which can occur with “some” self-watering pots. The theory is the disk prevents the roots from penetrating into the water reservoir below the disk, but in my curious mind, I wonder. I’ve seen roots creep where they want to go – nature finds a way, but again – I have not researched this like a scientist – it is just my intuition that the roots may try to go below that disk and hit pure water, and stop growing.

What happens when things are too wet? We humans may develop a foot fungus and stinky feet, and run to the drug store to get athlete’s foot powder. But plants, well, in containers and patio pots, their little roots aren’t going to be able to leave to get powder or more air. They are trapped. This is very unlike roots of plants growing in the ground where they can travel, plus they also have a larger mass of soil to help out the situation. Thus, my concerns about self-watering pots continue to ponder me. Here are some of my concerns:

Salt Build-up

Salts – Fertilizers are basically salts (in chemical form, as I remember my professor emphasizing in class). When applied near water, salts will move gradually towards the area where it was applied. This dilutes the fertilizer and distributes it. If tender roots are close to the fertilizer when too much fertilizer is applied, water is ‘drawn from the roots,’ and nearby soil (water in the roots and water in the soil moves). Plants can dehydrate when we apply too much fertilizer because of reverse osmosis where the water will move out of the plant’s roots, and this is why we use caution to apply fertilizers in the garden and pots in correct amounts, at the right time, etc.

In containers, salts can sometimes be a problem if they don’t leach out of the pot and end up building up in the pot (which doesn’t happen if you follow Container Crazy CT’s 5 Must Do’s for Container Gardening). You need to use good soilless mix with proper pore space, have drain holes in the base of your pots, and not over apply fertilizers.

Water should drain through the soil. It just makes sense. Also, it is a good practice and healthier for the plants, if you allow the soil to dry out a bit between watering applications so the soil has a chance to breath. Keeping the soil constantly wet is not good (unless it is a bog plant or native to a wet habitat or environment). Just like soggy shoes would bother our feet after a long walk in the woods, so will roots be bothered by overly wet soil for a long period of time.

A note on Winter Watering

In the winter, by the way, watering container gardens which you have moved inside as a houseplant is greatly reduced because the plant’s growth usually slows down if you place the pot in a sunny but cooler temperature inside the house. And those pots which you put in your unheated basement to go dormant are watered only when the soil goes dry – water very sparingly, as discussed in my “Storing Tender Tropical Plants” demonstration last weekend. Winter watering is greatly reduced in most cases.

Too Much Rain

Too Much Rain

Rain Falls

Rain – If you have self-watering pots outside in the summer, without a plug which enables drainage, and you get lots and lots of rain, the pot actually starts to form a pond on the surface of the soil because the excess water has no place to go. It goes up as the soil gets waterlogged. Now your plants are floating in a muck as the water rises to the top, and you’re not too happy either because you have to go outside in your muck boots and rain coat to relieve the plant by removing the plug in the weep hole in the side or bottom of the pot so the water under the disk may drain out. You may even have to tip the pot to the side to drain out more excess water. When we drink too much, what happens to us? We get messy too. We topple over or lean; the same thing happens with plants. They’ll wilt and eventually – if they drink too much – well, you know what happens there. They die or suffer such a bad hangover, they don’t quite recover, start to get diseases, rot, etc. One alternative solution, other than calling a rehab center, is to use plants that drink responsibly. Those which don’t require too many libations – as we discuss when we talk about drought tolerant plants, or just face it – water our plants ourselves to control and maintain an appropriate balance of watering applications.

Oxygen to Breath

Oxygen – Plant roots need oxygen to take up water. A perfect soil gives plant roots oxygen for respiration, pore structure, nutrients, and even distribution of water. When water is sitting in the base of a pot and the roots hit pure water, they will not grow there due to lack of oxygen. This reduces the root mass for the plants above to thrive. I like to give my plants what I refer to as a ‘full spa treatment’ by providing a good, if not great amount of soil volume by using large pots – something I go over in my Container Garden Workshops every May. They will be happy and thrive, grow large and lush, and full in BIG pots. Also, remember self-watering pots have a disk in the bottom. This reduces the amount of soil allowed in the pot above the disk because it is partitioned off. In small pots, the soil volume can be cut in half as compared to big pots. This greatly reduces space for the roots to grow and roots are important – very important to successful growth of your plants above the soil. It also causes a perched water table situation – an area roots seldom penetrate where root problems start due to lack of air, oxygen, etc – I try to explain the perched water table in my workshops as best I can to my attendees so they understand how small pots reduce the impact and vigor of plants. After they hear what I have to say on the subject, they go out and get that big pot – and let me tell you, they are impressed with their results.

The Fill Tube

In self-watering pots, there is a fill tube attached, and I don’t like it. Call me picky, but this is another reasons why I feel a bit leery about self-watering devices because there is no “spa” once the growing spaces are reduced – and we all know, everyone, even plants, enjoy a good spa environment. The fill tube is cumbersome basically. It is like a straw. I’m not going to fill a little straw to water my plants, ugh.

Drainage is Key

Drainage – As water enters your pot from your watering wand or rainfall, it moves through pore spaces in the soil and between soil particle’s tiny spaces. As it enters, it pushes air out. If air is not replaced over a long period of time, the plant roots will lack oxygen needed to thrive. Some water is used by the plant, and some will drain out through the mandatory drain holes in the bottom of your pots. It is one of Container Crazy CT’s 5 Must Do’s – drainage holes. If there are no drain holes, as with self-watering pots, some air is not replaced, in my humble opinion and experience. Too much water is not a good thing, nor is too little watering – it is a balancing act. Excess water causes the roots to suffocate because the pore spaces are filled with water. Basically drainage holes plus your commitment to watering correctly provides a balance. Some self-watering pots have “weeping holes” to help alleviate potential water build up as noted above. I suspect this “draining issue” is why the weeping holes were added to self-watering pots in the first place. Are they self-sufficient now? I don’t know – I need to keep researching, but I do know that I don’t want to take a plug out of a pot every time it rains – I only like to uncork wine bottles. Now, I see maintenance, watching if the soil gets too wet, and maybe I’m just anal. So, I’ll stick to just watering it myself.

Watering container gardens correctly and using the right soil-less potting mixes has provided me with the ultimate success in growing lush, bold, and beautiful container garden plants. In fact, I don’t always fertilize my containers and they are spectacular. My theory is: a) I water them, b) I use big containers with drain holes for large soil mass, and c) I use the right soilless mix, and of course, d) I love them (maybe a little too much).

Gravel at the Base of a Pot?

I remember thinking that putting gravel in the base of a pot for drainage was not really a good idea because it gets all clogged up eventually with little debris or bits of soil going into it over time, water then doesn’t drain there, roots don’t grow into that area because it gets too wet. Soon enough science later backed up this suspicion by announcing the old practice of putting gravel in the base of pots is not really beneficial. It can impede drainage. Roots won’t grow into that wet area at the base of the pot, thus it reduces the full spa treatment. So, take this as just my opinion on self-watering pots, and if I change my mind – I will update my findings here on this blog. I am sure someone will argue the point with me – and I fully admit I need to know more – but I also have heard some folks say they like self-watering pots, but I haven’t seen their plants though either. Are they healthy, lush, and thriving?

Planter with succulents by Cathy T

Planter with succulents by Cathy T

We all Need to Drink Responsibly

Lastly, there are always the options of using plants that drink responsibly such as succulents, some herbs, ornamental grasses, some shrubs like Junipers, or cacti. Drought tolerant plants require less watering, which not only saves you watering time, but helps the environment by reducing water usage – which is big today – no one likes waste. And if you are not a fan of dessert scenes or rock gardens, add things like soil moist to your potting mix, which is discussed in Container Crazy CT’s annual May workshops as well. Rain barrels may be placed on your deck too to obtain free water for watering your patio pots. You may focus on shade tolerant plants that require less water routines versus the hot, sun-loving types. And shade cloths can be used on extremely hot days in your greenhouses or growing rooms, or patio umbrellas on your deck during the hottest sunniest days of summer to cast some shade over plants to reduce watering needs. But I say, if you love beautiful plants in container gardens – then love watering them too.

Cathy Testa
containercathy@gmail.com
860-977-9473

To hear more about pot types, see this page: Container Garden Pot Types.

Watering your Container Gardens and Patio Pots on Very Hot Days

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During my Container Garden Workshops, held in May every season, I go over watering tips. It is a science and an art – and folks get a little concerned about how to water. One of the best tips is to stick your finger into the soil a few inches down or up to your knuckle, and if it is moist AND the plants look fine, you are probably okay. If the soil is dry and it’s a very hot summer day, it is time to water.

However, we are now in the month of August, and the soil in your patio pots may be a little harder/firmer, the plants may have consumed the soil mass somewhat, and this month can be one of the hottest points of the season, thus our watering routine becomes a little trickier.

To make your plants last well into autumn, it is important to remember to water appropriately when we experience “very hot days” that are well into the 90’s – such as the past two days we just experienced.

Here are 10 tips for those types of hot days at the end of the season:

Join the Early Birds – Get up early to water, if possible. As soon as it is light enough outside to see (providing you are an early riser like the birds) – water your plants before the sun fully rises. On hot days, like we just had which were up to 90 degrees outside, as soon as the sun was above the tree tops, it got hot quickly. So out I went in my PJs to water. There are so many woods around my property, the neighbors did not get frightened, thankfully. If you are able to do the watering routine early, it will keep you cool, plus watering in the morning is usually best for the plants too. It enables the plants to take up what they need before the soil moisture evaporates as the day warms up.

Skip the Heavy Watering Can – Attach a watering wand to your garden hose and drag it to your container garden locations. It is way easier than using a watering can which requires constant refilling and carrying. Also, while you are at it, if you have any extra watering cans or water bottles, place them near your pots and fill them with water at the same time for the next day’s watering to save a step or water on the fly. Another good choice is installing a rain barrel on your deck or patio to capitalize on rain water harvesting to use for watering your plants. I like to recycle the big cat litter jugs as containers to hold water when I need to water container gardens not reachable by the garden hose. They are large and easily washed out before the first use.

Fill watering cans or recycled jugs and set aside to have next day for watering on the fly

Fill watering cans or recycled jugs and set aside to have next day for watering on the fly

Relocate the Plants to Shade – I actually did this on Tuesday; I moved a couple of my big pots to a shadier location because it was that hot out. It helps with water loss from the soil and the shade will cool the leaves of the plants. Use a hand-truck if you have one to do the moving of the pot in order to avoid injury to yourself. It may be a pain to consider moving your pots, but in my case, it was worth it for one or two.

Use Your Eyes – Look for any plants which are potentially distressed, as in weeping, leaning over, or have leaves which are dropping or wilting. They may be experiencing drought or lack of moisture in the soil. Treat those plants like 911 candidates. When we have high heat like this – go water them first because when moisture in the soil has reached a point where it cannot meet a plant’s need, the plant may die. In these situations, the plants cannot easily recover from their water loss. In the trade, this is known as a ‘permanent wilting point’.

Dip in the Pool – Not the plants but YOU if possible. Okay, perhaps this a luxury because you may not have a pool or the time before heading to work, but if you have a lot of patio pots and container gardens, make sure to take a break to cool yourself off too if you start to sweat profusely out there – I know I did even early on Tuesday morning. Make sure you are hydrated first, or take a break by going inside if you get too hot after visiting all your plants.

Capitalize on Patio Umbrellas – Open a few up if you have them near your patio pots to cast some shade above them. Even the most heat and sun loving plants will appreciate this on hot days like we’ve just had. Especially if it is very sunny out too. While most sun loving plants can take it – if we have a super heat wave, the shade of the umbrellas doesn’t hurt for a day or two.

Snip Off Scorched Leaves – If you have some leaves with dry brown brittle areas, or leaf scorch on the edges, use your “clean” sharp pruners and snip them off. No sense in having a plant expend energy on a bad looking leaf with damage. Plus, around this time of year, August, many plants may look a little tattered anyways, so do some cleanup if you can at the same time as watering.

Water Your Feet – If the sun is so hot, the surface of the deck or paved area where you may have placed some of your patio pots and container gardens is too hot to handle barefoot, water your feet as you walk around – it may not help the plants but it will help you stay cool and feels good. Kind of like your own watering treat!

Direct water to soil, not on foliage of plants

Direct water to soil, not on foliage of plants

Water the Soil, not the Leaves – One of the most important tips is to direct your watering wand or watering can to the soil, not the leaves. Sometimes if the hot sun hits a leaf surface with water droplets sitting upon them, it can magnify the situation and cause brown spots on your leaves from burning/magnification. Also, water sitting on leaves on humid days can lead to fungal problems or diseases. Showering the tops of your plants will not get the moisture penetrated into the soil mass where it is most needed.

Gazing Ball Cracked, Watch Out for Hot Days and Cool Water on Glass Decor

Gazing Ball Cracked, Watch Out for Hot Days and Cool Water on Glass Decor

Watch Out for Glass Décor – A gazing ball cracked in one of my container gardens when the cool water hit the hot glass surface on a very hot day while watering recently, and it, unfortunately, cracked. This was a first for me so maybe a bit of caution there for any glass décor on an extremely hot sunny days in your patio pots and container gardens.

A cart filled with tops of summer plants after the summer season is over

A cart filled with tops of summer plants after the summer season is over

By the way, if the soil is shrinking away from the sides of your pots – you may be under watering in general; the soil is too dry, or if you are watering a pot which has held the plants for several years (as done with many house plants), maybe it is time to re-pot it with new fresh potting mix soil for potted plants.

Old Potting Soil Is Hard to Rewet

Potting mixes cannot hold moisture well after several years and are difficult to get moist (rehydrate) again over time. If you see crust on the top of your soil, this is usually a sign it is time for an updated soil environment for the plants. The soil has become like an unusable sponge that just won’t retain water anymore, it is exhausted. Take the time to repot it – you will be impressed with the results.

Yellowing Leaves on the Bottom of the Plant Can Be From Ovewatering

Conversely, if the bottom leaves of your plants are turning yellow, this can be a sign of over watering. Overwatering is not better, there needs to be a balance. And if your plants are in a shady cool location, they may require less watering routines, such as every other day instead of every day for those in hot sunny locations. And of course, the type of pot can make a difference in rate of evaporation (e.g., clay is very porous and dries out faster, black pots heat up faster in the sun, glazed pots can get hot too, etc.)

Watering Draining From the Bottom for Hanging Baskets

Many references will say to water your pots until the water drains from the bottom, but I don’t agree on this necessarily for really BIG pots (approximately 25” or over in diameter with about a 2 ft. depth or deeper.) Big pots hold a lot of soil mass, it won’t drain from the bottom immediately as you are watering, like you would see with a hanging basket.

When watering your hanging baskets, watering until it drains from the bottom is needed because they dry out fast. For really big pots, you want sufficient moisture but drowning them is not the answer.

Allow the Soil to Dry Somewhat Between Watering – Let it Breathe

Also, another important note is you should allow the soil to dry between watering routines. There needs to be a balance because the plant’s roots need both water and oxygen. If the soil is constantly wet all day long, this can lead to problems, even root rot over time. Think wet feet in sneakers, not a good situation. Good soil mix specifically for container gardens and patio pots helps to provided the balance in the root area from the start of the season, which is one of the “Cathy T’s 5 MUST DO’s for Success“.

Bottom line, there is a ‘yin and yang’ to watering plants, but you will get it sooner or later – and more of this is covered every year in my workshops because it is something of utmost importance to my attendees and the plants in their beautiful container gardens.

As the fall approaches when the days start to cool and are shorter, the watering routine is reduced and eventually subsides. You won’t need to water every day as you have been doing in the summer months. Things will calm down and soon it will be the time to take down your container gardens.

Storing Tropical Plants Demo in October

By the way, my demo day on how to take down plants for winter storage is posted under the “Nature with Art Class Programs” on this blog’s menu bar. It will be held Saturday, October 17th, at 10:30 am to 11:30 am in the Broad Brook section of East Windsor, CT. You may sign up via the links above where you will find the “contact form” or by visiting my business Facebook page. Private sessions at your home are available also. The session is listed under the EVENTS. Just click to sign up.

Thank you,

Cathy Testa
960-977-9473
containercathy@gmail.com

P.S. Watch out for spiders – They seem to be hanging around quite a bit lately!

Spider Hanging Around on Faucet

Spider Hanging Around on Faucet