Adding a Pond To Your Garden

One of the most exciting projects we have going this fall is completing our garden pond. It all started when we decided to remove a pine tree that had been inconveniently placed by a previous owner of our home. When the stump came out, we were left with a hole in the ground. My partner loves to dig so much you’d think he was a badger, so he has enlarged the excavation bit by bit over the past couple of years. (At our age, shovel and wheelbarrow work has to be done in small episodes.) To begin constuction, we first establish the highest water level, then we work outward in opposite directions from that point, laying a row of cinder block to form the top edge of the pond. We have seen photos of pond construction in which the soil itself was cut and contoured. Not only is this hard work, it is difficult on a sloping site. Using cinder blocks makes the job much easier. These are "FHA" blocks, with a solid concrete bottom. Once leveled on compacted soil, they stay in place better than standard blocks.

(As the image illustrates, all construction work on the property is overseen by PJ, our Boston terrier.) It is essential to the appearance of the finished pond that the top rim be as level as you can make it all the way around. Otherwise, the liner will be visible above the water line if you leave a low spot, and this will ruin the "natural" effect. Once the top course of blocks is in place, the remaining levels can be installed using the top course as a reference.

The pond will have three levels when completed. The deepest area in the center will be kept free of plantings, and will hold the pump for a planned small waterfall. The waterfall serves not only a decorative function, but also oxygenates the water.

The second level will hold tubs planted with water lilies. We plan on using only two or three compact-sized varieties. Otherwise, the pond can become overcrowded in too short a time frame. As a rule, water lilies should be divided and repotted every three years. This can be a daunting task, as they can grow profusely in that time. On the other hand, lily pads shade the pond, which helps keep the water cool for the fish and lessens algae growth. We recommend that about two thirds of the surface be covered. The upper level is for emergent plants. These are species, such as cattails, that like wet feet but grow up from the water surface. We have dozens of varieties of such plants to choose from, and our research is ongoing. We will be posting a complete planting list here, once we have our plans completed.

The current grade slopes slightly, so we have constructed a retaining wall on the uphill side of the pond. The surrounding area will be brought up to the level of this wall and re-paved.  We are using precast concrete pavers set on a gravel base. Pavers are not only easy to install without heavy equipment, they are also pervious to rainfall, and don’t interfere with natural drainage. Posts for a guardrail will be installed before paving. The wooden arch bridge in the lower right corner of the image will be replaced with a new bridge. Up to this point, it has served to get across the French drain that carries water away from this side of the house. This water will now be stored in the pond. We can re-direct the flow into another French drain when needed by means of a water gate. The excavation for the overflow is barely visible at the right of the image. It will have the appearance of a creek bed when completed and will direct water to a bed of moisture loving plants, such as cardinal flower.

The pond will now be allowed to settle for a few weeks before we install the liner. Once the liner is in place the pond will be filled with water and again allowed to settle before we begin the fun part: installing the natural stone coping and rock work. The finishing touches will allow the pond to blend with the rest of the nature inspired landscape in our back yard. We will also have "planting pockets" here and there in the rock work.

We will have more to say about garden pond construction and maintenance in future posts. A small pond is a great way to put into practice the permaculture principle of increasing diversity in the landscape. Besides plants both edible and ornamental, and fish, a pond offers habitat for dozens of varieties of insects and amphibians, along with countless micro-organisms and tiny invertebrates. Properly sited, a pond can assist with water management and make great use of an otherwise marginally productive area. Using marginal areas is another principle of permaculture.

Beating the Heat

I do not claim to be able to fortell the future, but I was certainly anticipating a hot summer when I filled this old firepit with soil and planted a collection of heat-loving annuals. Since the planter was once a firepit, I chose a fire-inspired color scheme. Black coals, gray ash, yellow sparks and red flames, supplied, respectively by petunia, dusty miller, lantana and coleus. All of these are southern favorites owing to their tolerance of heat and humidity. This summer, they are getting a real workout!

We have been days without rain here in the Tennessee Valley, although some folks have had the benefit of afternoon showers that are a common feature of summer weather around here. In my particular case, we have had no measurable rain in the garden for two weeks, and have been irrigating like mad. Despite the irrigation, the soil is drying out and cracking in places. Shrubs and trees are showing signs of heat and drought stress. No amount of irrigation can make up for a good, soaking rain.

Vegetable production continues largely because of our irrigation. We used 5600 gallons of water last month, according to our utility. This month, I expect the total to be at least double that amount. Fortunately for us, the utility caps sewer charges at 6500 gallons during June, July and August, so gardeners get a small break on the water bill (as do swimming pool owners and habitual car washers).

Fresh, potable water is a precious resource in most of the world, a fact lost on us in Tennessee, where waer is abundant. The city of Knoxville removes barely a tenth of the water that flows past us in the Tennessee River each day. With average rainfall around an inch per week during normal times, we are poster children for the old adage that water is never missed until there is a dry spell. But we gardeners really should always be thinking about saving water, not only because conserving saves money, but because waste is inconsistent with sustainable living. Here are some tips for reducing your water consumption this summer:

Install rain barrels or a holding pond to collect and manage runoff from your roof. It will rain again, eventually, providing you with free water.

Mulch, mulch, mulch. Although much of the water lost from the soil is transpired by plants growing there, mulch helps to keep soil moisture relatively constant between irrigation or rain events. This is important for summer crops like tomatoes and cucumbers that appreciate evenly moist soil.

Irrigate early in the morning or late in the day to minimize losses from evaporation. Use a hand held hose sprayer, rather than an overhead sprinkler. This allows you to give some plants more water, and hold back on water for the more tolerant denizens of the garden. Sprinklers waste a lot of water that evaporates before it reaches the ground, especially on punishingly hot days like we have had lately.

Anticipate summer dry spells and include drought-tolerant plants in major plantings. Most trees and shrubs, especially those native to the region, fare well in summer once established. If you have plants that demand irrigation just to stay alive, consider if they are worth the effort or if you might be wiser to replace them.

After the above was written, the weather finally broke. Thursday evening, July 5, we received 0.66 inches of rain. Unfortunately, the weather system that brought us rain and winds also brought far more severe weather in other parts of the region. Two people died in the Great Smoky Mountains. We accept the rain with gratitude, and count our blessings.