Tips for Retaining Water in Gardens and Containers

In fact, not just practical solutions, but economical, feasible, already-have-the-answer-in-my-garage solutions.

A master gardener with Phipps Conservatory since 1999, Holt often speaks at gardening groups in the Pittsburgh area and recently traveled to the Philadelphia Flower Show to give a seminar. Since “Wonders of Water” was the theme for the flower show this year, Holt decided to teach gardeners about some of her water-conserving ideas in a seminar during the show.

Holt said she gravitates to easy-access, economical ideas that help gardeners “solve (their) problem right now with things that (they) have on hand.”

For instance, one of her tips — a new version of an old idea — is to punch tiny holes into a gallon milk jug, then bury it up to the neck of the jug before filling it with water, letting that water slowly seep out next to the plant, and refilling it throughout the growing season.

Historically done with terra cotta years ago, when gardeners sunk unglazed pots called “ollas” (pronounced “oh-yah”) next to their plants, a milk jug or soda bottle will work just fine as modern-day subterranean irrigation.

“You can actually direct it if you want it between two plants, so you can customize your watering system,” she said, adding that she pokes two small holes on either side of a jug, then sinks it between two plants.

“I like a milk container better than soda bottle because the soda bottle mouth is very small, while a milk jug is actually large enough to get the hose down in it, so it’s a little bit easier,” she said.

As far as how to tell if your plants are thirsty, Holt recommends planting an indicator flower.

“Chrysanthemums are a water indicator,” she said. “They wilt first when water is needed in your garden, so you can plant them throughout your garden.”

“When they start wilting, then you know that your plants that need more water will start wilting soon — so they’re kind of a sacrificial plant,” she said.

Holt has another idea for slow-release watering of plants.

“One problem you’ll read about is that your tomatoes are not getting enough calcium, so people put eggshells at the bottom. But, calcium can’t jump into the plant — the problem is uneven watering. When it’s really hot and soil dries out, and then you water it and soil is really wet — you have to have even watering to avoid that,” she said.

“One way to keep the soil moist more evenly is to dig a giant hole, soak some rolled-up newspapers (as in, a whole newspaper rolled up) in water, and put that in the bottom of the hole,” she said. By lining up five or so soaked newspapers side by side, the gardener creates a wicking system that keeps the plant’s roots moist and draws and holds more moisture throughout the growing season. Finally, she said, “Put some soil in that hole and plant a tomato over the whole thing,” she said. “It’s kind of like having a moisture reservoir.”

To effectively plant the tomato over the newspapers, Holt recommends gardeners cover the newspapers with 8 inches of soil for root penetration.

“Then plant your tomato on top of that,” she said. “The newspaper is not going to hurt the soil and it will break down and eventually be compost anyway.”

To help house plants stay hydrated for a few days without water, Holt recommends making a “little round topper” out of newspaper. She selects several layers of newspaper, staples them together securely, then cuts a circle according to the diameter of the pot, cutting a line into the circle to help fit it around the plant. Next, she soaks it well and carefully lays it on top of the dirt at the base of the plant.

“It’s not a long-term thing, like for 10 days or so, but it’ll keep moisture in there,” she said, adding that the topper should be removed after a few days so it doesn’t start to deteriorate and fall apart. “It helps hold the moisture in there and you don’t have to call your neighbor over” when you leave the house for a few days, said Holt.

Holt also recommends careful planning when deciding where to locate plants in a garden.

“Make sure they go together,” she said. “We check for sun or plant height needs, but we don’t always match up with water needs.”

For instance, she said, “Begonias need a lot of water, while creeping jenny doesn’t need as much water,” so don’t pair those two plants in a container.

To help gardeners keep their containers organized, Holt offers her “key ring” tip.

“When you go to the nursery, you have a million plants to choose from. So, you finally make a selection, come home and put it in the wonderful pot that you’ve designed, and it turns out perfect,” she said. “Then, next year you can’t replicate it, since you don’t remember what it was.

“So, punch a hole in the (label) tabs, markers, (that come with the plants in their pots) and put it on a key ring and mark it “front hall pot” or “always buy this one,” or “this one doesn’t work,” Holt said.

“So, if you have a key ring, for a favorite planter or window boxes make these little mini research tags instead of doing a diary. … Just put (the tags) on a key ring and then you have your records. Then keep your key rings in your car, so when you go to the nursery, you have your key ring right there and don’t have to worry about what to buy, or worry about the diary that’s sitting back at home,” she said.

Holt also discussed her ideas for winter water help.

“The worst thing that can happen for a fish pond is to have the ice completely over it because it causes gases underneath and the fish will die,” she said.

“You’ll see people out there with a shovel and they end up breaking the liner underneath,” she said.

Instead, Holt recommends that gardeners “go in the kitchen and get a pot, put that on the ice and then pour boiling water in the pot,” she said.

“If it doesn’t go through the first time, pour that off and pour more boiling water into the pot. The boiling water will melt the ice, leaving a nice round hole for gases to escape and happy fish underneath. Don’t forget to knot a string onto the pot and tie it off onto the lawn chair that you forgot to put away or you’ll have all your Revereware on the bottom (of the fish pond),” Holt said.

As for creating moisture-retaining mulch in her vegetable garden at her home, Holt uses newspapers and straw on top. However, around shrubs and planting areas she uses shredded leaves.

Holt also groups flowers that need a lot of water near the water source, such as a hose or creek, for example.

“In other words, don’t plant your cattails on top of the hill,” she said.

Gardeners have to be realistic about how much water they will feel like carrying to plants during the growing season.

“If they (containers) are not looking good or need constant care beyond your gardening habits, then eliminate them,” she said. As an alternative, plant drought-resistant herbs in a container or window box if it’s going to be a struggle to get water to them.

Lastly, Holt said she always carries her watering can backward to avoid soaking her shoes as she transports water. “I don’t care of it’s 90 degrees, wet socks never feel good,” she said.Photo by Michelle Kunjappu

To help house plants stay hydrated for a few days without water, Chris Holt recommends making a “little round topper” out of newspaper.