What should you know about watering plants in containers?

Watering plants in containers doesn't sound like rocket science, but can make all the difference to the health of your plant. Here are 7 tips for watering plants in containers.

Water Deeply - The most important thing when watering plants is to give them a good, long drink - optimally, until water runs out the hole in the bottom of your container. You do this because, depending on the size of your pot, many of the plant's roots will be down towards the bottom and you want them to be able to get water too. It will also encourage roots to grow down toward the bottom of the pot, which is better for plants.

Check Moisture Level - Before watering plants, check to see if your plant really needs it - the top of the soil can look dry, even though just below the soil line it is still moist. Stick your finger into the soil all the way to the second knuckle. If it feels dry at your fingertip, your plants need water.

Know Your Plants - Most plants prefer to live in moist soil, not wet, just damp. Fortunately with modern potting mixes, which are designed for good drainage, this is not impossible. However, different plants have very different moisture needs. Some plants like to be dry, some like to be a bit dry between waterings and then there are those delicate plants that, if they get even a little dry, will swoon and drop all their buds and leaves. However, as a rule of thumb, flowering annuals don't like to get too dry. Succulents like to be a bit dry and vegetables - particularly those that are juicy (tomatoes, cucumbers, melons) - like to be kept moist and need a huge amount of water. Some herbs (basil, rosemary, thyme, dill, oregano, cilantro) like to dry a little between watering and the flavor will be stronger if they do. Some herbs like (parsley, sage, chives) like more moisture. One way to keep track of your plants' watering preferences always nearby is to keep the plant tag, either under the pot or buried in the soil.

Water in the Morning - According to Horticulture Magazine, plants' roots are more receptive to watering in the morning and the evening and less so in the midday sun. However, it's not a good idea (if you can prevent it) to water in the evening, because when you let water sit on the leaves overnight, your plant is more likely to contract some plant diseases, like mildew. That said, if you get home from work and your plants are dry, even if it's in the evening, give them a good long drink.

Water the Soil, Not the Leaves - It turns out that some plants - ones with hairy leaves - are susceptible to sunburn if you get water on their leaves in the sun. Water droplets can act like mini-magnifying glasses and burn your plant. Even if your plant's leaves are smooth, it is still a good idea to water the soil and not the leaves, if you can. Wet leaves can lead to an increased chance of fungus, mildew and other diseases.

Don't Rely on the Rain - Even if you think that a rain shower has watered your plants, check anyhow. Sometimes a plant's foliage and flowers can act like an umbrella and actually keep water from getting to your soil - shedding the moisture right out of the container.

Don't Let Soil Dry Out Completely - Most potting mixes become tough and won't absorb water efficiently, if you let them completely dry out. Your potting mix can also pull away from the sides of your containers when it gets too dry, so while you may think you are giving your plant a good drink of water, the water may be just flowing over the soil, going down the sides of the pot and out the bottom, leaving your plant gasping for a drink. If you do let your soil dry out, you have a couple of options. If your pot is relatively small, you can take the whole thing and submerge it in a larger container of water, taking it out when it has stopped bubbling. For a large pot or one that is difficult to move, poke holes in the soil with a pencil or skewer, and then give it a good drink, making sure the water is penetrating the soil and not just flowing down the sides.

Don't Assume Once is Enough - Depending on the size of your pots, and the kind of soil you use, don't be surprised if you end up having to water your container gardens more than once a day. Heat, wind and dry air can quickly parch your plants. Terra cotta pots, hanging baskets made from coir and metal pots all can dry our ridiculously fast on a hot, windy summer day. Over the season, you will probably get to know which containers need to be checked more than once a day, but when they are first planted, it's a good idea to check your containers in the morning and again in the afternoon. Until next time...Happy Gardening!!

TEXAS-TOUGH CONTAINER GARDENS

Plants, pots, and potting media that are unfazed by heat and drought

The whole world seems to be in love with container plants. So much so that some gardeners can’t control themselves—their whole gardens have gone to pot!

Texans have embraced container plants since the earliest Spanish settlers first introduced the concept. After all, they make great mobile horticultural displays. They provide added architectural interests in their construction form and materials. And, of course, they allow those who don’t own a piece of terra, or the ability to reach the ground, the opportunity to garden. Many a patio, deck, and porch can thank containerized gardening for its comforting greenness.

Form And Function

There are many kinds of containers on the market, ranging from relatively inexpensive to “if you have to ask how much, you can’t afford it.” To be quite honest, however, most plants don’t care what the actual container is made of, or what it costs. Homemade containers and recycled containers are just fine if they fit your design theme. At my place of business, I happen to own more than 15 crown tire planters myself! (Don’t try that in your suburban neighborhood.) Plants only demand that the chosen container hold a proper growing medium and that there be a drain hole at the bottom.

Although pots are available today in myriad artificial materials as well as natural ones, terracotta clay pots still remain the most popular. In my horticultural experience it’s pretty much like everything else “ you get what you pay for.” Experience has shown that clay pots from Italy are high quality and long lasting, while inexpensive clay pots from domestic sources tend to succumb quickly outdoors. Mexican clay pots also seem to break down relatively quickly.

Generally, the thicker the clay and the longer it’s fired, the longer it will last. My favorite long-lasting clay pots are those made of white East Texas clay in Marshall, Texas, by Grubb pottery. I’ve never had one even think about falling apart. I even still have some that once belonged to my Grandmother Derestine and are now considered to be family heirlooms. Grubb has been making them for over 100 years, so they obviously know what they are doing.

Container Basics

The very first thing to consider when choosing a container is the size it will be. Just remember, the larger the pot, the less you will have to water it. Also remember that it’s a myth that adding pot shards or gravel at the bottom of the container will make it drain better. It actually makes it drain less.

However, too much drainage is a bad thing as well. Drying out during our hot summers is the limiting factor in container gardening in Texas. Due to the added gravity and the limited root-growing area, all plants in pots will dry out faster than the same exact plants in the ground. For this reason, I suggest only growing drought-tolerant plants, only using large containers, and only using a soil mix that retains moisture. This normally means the predominant ingredient is sphagnum peat moss. Bark-based potting soils often require watering as often as several times a day during the hot summer. Anything more than once a week, I deem a horticultural design flaw. I’ve even been known to break a basic horticultural rule by filling up half or two-thirds of large containers with clean topsoil and then topping it off with high-quality potting soil. The topsoil helps decrease the drainage and reduce the costs.

But, the best all-around soil mix for most showy bedding plants is a professional peat based potting soil containing sphagnum peat moss, vermiculite and perlite, with a slow release fertilizer like Osmocote added. It’s important to use a slow-release fertilizer in containers, as water-soluble nutrients are prone to draining right through the pot and being totally wasted.

The Planting Plan

You have the option of using plants that persist year-round, like evergreen shrubs, succulents and groundcovers, or rotating color plants adapted to particular growing seasons. The primary seasons for specific plant growth in Texas would be cool-season (late fall, winter and early spring) and warm-season (late spring, summer and early fall).

A typical color rotation would include frost-tolerant plants like pansies, dianthus and ornamental kale when the cool temperatures arrive. These plants would then be replaced by mild-temperature-loving selections like petunias, verbena and Geraniums in spring, or perhaps heat-loving tropicals like firebush, esperanza and copper plant that would all last until the first frost. I personally suggest skipping the “spring” plants and only using the tough, heat-tolerant tropicals, but it’s entirely possible to include some of both in mixed plantings and let the heat-tolerant summer plants overtake those that perform best in the spring.

One of the benefits of container gardening is that the limited area makes it much easier and more economical to change out color schemes on a more frequent basis to suit your design taste, or the often-changing Texas climate.

A Better Option

In the past, I maintained numerous containers that were changed out frequently. As I’ve gotten older and wiser, I’ve staring limiting the number of containers that I use and place them closer to sources of water. My current interest is experimenting with succulents that don’t require any additional water (other than rainfall alone). Yuccas, Agaves and their varied relatives are literally living sculpture and make great container plants in Texas.

High-maintenance or low-maintenance, annuals or perennials, homemade pots or imports, there’s something in container gardening for everyone. Just try somehow to contain your enthusiasm! Please allow me to apologize for not getting to all of your questions this column, I have been extremely busy with work and promise to get to them as soon as I am able. Until next time…Happy gardening!

Jimmie