Would a rainwater cistern save you money?

Once you start down the green road, it's pretty easy to get hyped about conservation - soil, water, building supplies, energy, savings. You would assume a rainwater cistern for watering your garden would save you money. This could be true, but depending on the size of your garden, the frequency of use and the cost of your system, it might actually take a very long time to see those savings.

The Biological and Agricultural Engineering Department at North Carolina State University has produced a free computer model that simulates a cistern for your garden based on historical rainfall data and and calculates how long it would take to recoup your initial cost in water savings based on the amount of city water usage replaced by your cistern. I capture water from 500 square feet of roof, and my cistern can store up to 500 gallons of water. I ran the model so that I watered my 600 sq ft garden 1" a week or 53.4 gallons a day, with waterings at 8am and 6pm during the months March through September.

Because my cistern was absolutely free, I am able to garner savings right away. However, if I had paid the $500 that systems of its size typically cost, it would take me 15 years to pay it off in water savings. The cistern replaced 57% of my city water usage. This calculation is based on whether there was water in the cistern when I was scheduled to do the twice daily waterings.

Out of curiosity, I switched over my design to a 100 gallon storage system (typical of a rain barrel or two small linked barrels) and assumed a cost of $100, I was able to start saving money on water in 6 years. The cistern replaced 31% of my city water usage.

So, before you jump the gun and ride the newest green fad, do the math!

This nifty model has rainfall data files and municipal water costs for most areas of North Carolina. I ran the model with "custom usage" rather than "irrigation" which schedules irrigation by demand based on historical PET estimates. I figured this was more representative of my watering habits.

What is a "Last Frost Date" and why should you care?

When I started gardening, there was one phrase I starting noticing on every seed packet: last frost date. Another one I heard almost as often was: last killing frost. I wasn't sure what exactly the difference was and who exactly determined that date. The Farmer's Almanac defines frost in the following terms.

Light freeze:29°F to 32°F—tender plants killed, with little destructive effect on other vegetation.Moderate freeze:25°F to 28°F—widely destructive effect on most vegetation, with heavy damage to fruit blossoms and tender and semi-hardy plants.Severe freeze:24°F and colder—damage to most plants.

When gardeners use the term "last killing frost", typically they mean a light freeze. When you first put your young seedlings, they are tender and can easily be harmed by frost. This date doesn't mean that there won't be another frost. It just means that 50% of the time, the last one will occur before the date, and the other 50% of the time the last one will occur after. There is usually a two week give or take around this date. In my region, the last frost date is March 31, but the window (90% - 10% probability) is March 15 - April 16. The conventional time to plant here is Good Friday. (Look up your date here.)

However, it doesn't take a frost or freeze to harm a plant. Some plants may look like they've survived a chilly night and dodged the freeze bullet, and you won't see the effects of the cold temps until later in the season. This happened to me last summer. I put my peppers out right at that last frost date along with the tomatoes. A cold snap came through, so I tented the garden with a tarp. The next morning, some peppers had been smothered by the tarp, but there were some that appeared okay. Guess how many peppers I picked last summer? None. At least none that I ended up eating. The summer before I'd had a bumper crop.

This is why it is important to know soil temperatures and what temperature your plants can tolerate. Peppers like the ground temperature to be above 65F and the night air to not drop below 50F. Your air temps could be high enough, but the soil may not have yet warmed. Here in my region, we don't reach 65F until May. Tomatoes like the soil to be at or above 60F - again, that's mid-April in my region or after that last frost four-week window.

So why is it that plants are available when there is still a high risk of frost and the soil is still too cold for the plants to thrive? I have my conspiracy theories, but my guess is that the people demand it. If the people demand it, the retailers will supply it and will be happy to sell them a new plant when the first one gets bitten!

BUT. If you are like me, you started planting your seeds very early and your seedlings are overstaying their welcome and may even be getting leggy from not enough sunlight. You can always consider a cold-frame or hot box (it's like a mini greenhouse), row covers, plastic mulch and hoop gardens. These will all trap heat in during the day and keep the air and soil warmer at night. If you are going that route, know that there is cost involved and use a thermometer to check and make sure you are getting the soil warm enough. I will keep moving my plants to the deck during the day and inside at night for the next two weeks.

Did you forget to start seeds indoors?

If you live in the Southeast, no doubt you've been bit by the Spring bug. You can't go to a grocery store without seeing displays of plants for sale. The Farmer's Markets are starting to buzz again and seeing all the fresh produce might make you want to get your hands dirty. Yet, what's that? You forgot to start your seedlings two months ago? That's right. Some of us gardening crazies started planting our tomatoes and pepper 8 - 10 weeks ago. The good news is, since that last killing frost date is right around the corner (remember, it's just a statistical date!) you can skip the whole window invasion and dirt in your carpet.

Many veggies are ready to be transplanted, and even more are ready to be sown straight into the ground. The only thing you've really missed out on at this point is getting to grow that truly unique tomato variety that the local nurseries and home improvement stores don't carry. Don't cry though - many places now carry tasty heirlooms and more than the standard big-better-bigger-yellow-boy varieties. Cost isn't too bad either. My local nursery is telling four-packs of veggies for only $1.49. Given all the work I've put into caring for the seedlings, it makes me consider just buying plants myself!

So now that we are fully in Spring, in my zone (7b) it is a little late to start early spring crops like broccoli, peas and carrots, but there will be another shot at those in the fall. Summer crops that start great from seeds outdoors: potatoes, squash, cucumbers, beans, melons, okra, corn, and herbs like dill, cilantro and basil.

If you are a new gardener and are giving a shot at your first raised beds, www.gardeners.com has a great planner tool that will let you take and altar their pre-designed kitchen gardens. Not only does it have fun layouts, but the designs come with planting tips for all the crops you select.

Good luck!

Too Much Water in the Garden?

It is raining again. The cistern is completely full, the French tile drain is at capacity, and everything goes squish when stepped on. There is more rain the forecast for tonight and tomorrow. Our garden sits on a small plateau that seems to retain water. Two days ago I dug out a dead hibiscus to discover standing water at the bottom of the hole and a big fat spider.

Currently all the paths are under water, which first blew my mind but then validated our decision to dig the paths down while building the beds up. There are still spots where the beds are too low and little seedlings are barely getting air.

Remember last year when I thought it would be cute to upcycle a sink into a small garden water feature? Remember how I pulled it out and filled the spot with rocks? Well the pond is back - not by choice.



When there is too much rain or when your garden seems to stay too wet, what can you do?

Wet conditions are usually caused by a high water table or water retaining soils such as clay. Occasional ponding or squishy conditions are okay, but if you start noticing a funny smell and have trouble with moldy sick plants, you may have too much water too often. There are several options for improving the space:

• Build up. You can do a raised bed or mound up the in-ground beds. This will add several inches to the root zone.
• In the same respect to building up the beds, recessing paths gives the water a place to flow away from the roots of your plants. 
• If there are tight clays, break them up and improve infiltration by adding compost and organic materials. Don't be tempted to add sand though - sand and clay make bricks!
• Install a drain pipe or French Tile drain to help lower the water table.
• Utilize the lowest spot to excavated a small pond. Water features can be attractive and draw in more wildlife. Just make sure that you want the wildlife to be there and have a plan for mosquito control.
• Plant according to the soils - if there is a lot of water, use water loving plants!

How to Bring the Magic to your Garden

Growing up, dad had a vegetable garden out in our front field in the middle of an old riding ring. To get there, we'd have to wade through weeds, keep our eyes open for snakes, and battle the blaring sun. I never had much interest in venturing out there unless it was a picking day and we were instructed to bring in the beans and clip okra.

As I've started my own gardens over the past few years, one of my goals has been to involve my kids in the various stages. Initially, I had a very simple view of letting my oldest have his own small box once he hit four, but I've seen that kids don't like to be boxed in - just like some plants! Daniel is now four, and that idea has totally been canned. The entire garden is designed to bring the magic, to draw them in and help them explore.

Here's several components that help me bring the magic:

• Winding pathways make every trek through the garden feel like an adventure, especially in the summer when the plants are tall and give a jungle feel to the place.
• Kid-size respites like benches and little nooks give them a space to sit and contemplate life.
• Tunnels and teepees provide shade and exploration. Kids love having secret forts and hiding places. All it takes are some trellises, bamboo poles or wire-remesh and some vining plants!
• Varying textures create a stimulating environment where they can push trucks and learn to dig. In the middle of our butterfly garden, there is what we call the "rock quarry" where we toss all the rocks we find. They love to load up the dump trucks with them.
• Something to climb on is essential for helping them get a change in view. My boys love climbing a five foot wood ladder and peek through the tall corn. They also climb the fence to look out on the back yard and watch birds. 
• Weird plants, plants with vivid colors, prickly plants, and plants that grow super tall create new places to wade into and explore.
• Naming our garden friends like the writing spiders has also helped them to appreciate the diversity of life and ease their fears of the unknown.

Early Planting?

So what exactly do we do with this? The next 10 days are predicted to be glorious (yes, rain is glorious too). The traditional planting date here is Good Friday, which this year is April 6. There's always a chance of a freak frost hitting right up to the end of March, but it is so warm out that rogue beans are popping up in the garden. I'll hold off on tomatoes and peppers, but I'm very tempted to plant some blackeye peas, beans and squash. What are your plans?

The Winter Carrot

After asking for weeks of Daniel begging to eat the one carrot we grew over the winter, I dug down around the top and saw that it was quite large and let Daniel pull it up. I had to chase him around the yard several times begging for a bite before he let me try it. For the size, I was expecting it to be bitter, but I guess the winter temperatures sweetened it up nicely. Both boys gave it a nibble, but they weren't impressed.

One carrot + three crazies!

Birds!

These critters have some amazing personality! I was able to leave the door to the deck open and capture some of these from inside my living room. The birds are quite pleased that I've started feeding them again.

Bluebird Box

This morning I spotted a pair of bluebirds checking out the box I hung last spring. Last spring, I hung the box just a little too late in the season and it's been empty all year. Sadly, after snagging this picture, my boys went screaming through the backyard, and the bluebirds flew off. I've enticed the boys back inside with animal crackers and Curious George, just to give the nesters a chance to realize my yard isn't that terrifying. I'm seeing some fluttering around the box again! I think I'll take the boys to a park since it is so lovely outside.