Did You Know? ET-Based Irrigation Controllers

et-based irrigation controllersET-based irrigation controllers? When you hear that you may think back to the early 80’s when E.T. was all the rage. But the ET I’m referring to has nothing to do with phoning home. ET stands for evapotranspiration. Evapotranspiration, as defined by the Irrigation Association, is the loss of water from the earth’s surface through the combined processes of evaporation from soil and plant surfaces, and plant transpiration. So what does all of this have to do with your irrigation system? Simply put…everything.

If you have an irrigation system in your garden you should be concerned with evapotranspiration. When you set your irrigation timer to water Monday, Wednesday and Friday for 30 minutes on each zone, your system will water the same whether the temperature is 70 or 90 degrees, whether there is a light breeze or 20 mph wind, whether the humidity is 40% or 90%. Unless you have a rain sensor on your system (which you should…they can be installed by a professional for less than $100), your system will water for 30 minutes if it rained 1/10″ or 2″ earlier in the day. What if you could have a controller that would take all of that into account and then water based on your plants’ needs. You can with an ET-based irrigation controller.

Hunter makes a very nice ET-based irrigation controller that I have personal experience with. Other irrigation manufacturers, including Toro, Rainbird and Irritrol, make ET-based irrigation controllers but I can’t speak to the quality of those controllers since I don’t have any experience with them. With the Hunter ET-based irrigation controller, you have your own weather station that records real-time data and converts all of that information so that your plants receive the water that they need. Here’s what it looks like:

hunter ET-based irrigation controller

It has a rain gauge, an anemometer that measures wind speed and a thermometer to determine the temperature at your specific site. When setting up the controller, you enter the following data that helps the computer determine when and how long to water:

  • Soil type
  • Slope
  • Crop being grown
  • Age of crop (new vs. established)
  • Sun exposure


This information is critical and the ET-based irrigation controller is only as good as the information that is entered at this stage. It is very handy to be able to enter different information for different zones according to their site conditions. Most landscapes have some sun and some shade, some turf and some landscape beds and some new plantings intermingled with the older ones. By entering and updating the information as conditions change, the controller is able to adjust the watering times and durations accordingly. Pretty cool huh?

So what does all of this cost? Well, that depends. If you already own an irrigation controller that is compatible with the ET-module, the cost is very reasonable…you can buy the module without the anemometer for the Hunter ET-based irrigation controller for $239.07 online. The anemometer is about the same price…so maybe you take baby steps in converting your existing system over….the choice is yours. While the upfront cost may turn you off initially, you should do the math to see how long the payback takes. Many localities are now charging a higher rate for water usage over a certain limit, aimed at users with irrigation systems. If you live in suburbia and have to pay sewer charges, the payback will likely take far less time unless you have a separate meter for your irrigation system. Also, consider the benefit of set-it-and-forget-it. No more adjusting your watering program when the temperatures soar to 95 degrees…the ET-based irrigation controller will adjust the watering times for you…yeah!

Of course, if you’re like me, my irrigation system is in the sky and it is completely at God’s will. If the rain doesn’t fall on my landscape, the plants don’t get watered. They’ll either live or die trying. My only exceptions to that rule are newly transplanted plants and vegetables. Since I don’t have a veggie garden at my house due to the abundance of shade, I don’t have that concern for now. Consider hugelkultur if you will be installing new beds in the future. It’s a way to garden without watering at all. That’s my kind of garden!

Let me know your thoughts about ET-based irrigation controllers…leave me a comment below or e-mail me at stacey@midatlanticgardening.com. Happy gardening!

Friday Free For All: Using Water Wisely

Well, it’s happening already. The Mid-Atlantic gardening region is dry. Granted, we have 1″-2″ of rain expected this weekend but the rain has been pretty negligible in central Virginia since the middle of March. I hope that this isn’t a sign of things to come this summer. My mind has been churning about how much water we use. Not just my family or community but as a nation…as a world. Water is a renewable resource but that doesn’t mean that we can use it with reckless abandon. Let’s delve deeper to look at how we can use water more wisely in our gardens.

  1. Hugelkultur – if you’ve been reading my posts for a while, you know that I am big fan of hugelkultur. It just makes sense…use wood that nature has provided for us to help plants through the dry spells. Check out the link for more information if you’re unfamiliar with the practice of hugelkultur.
  2. Reduce your plants dependence on irrigation – while it is vitally important to make sure that newly transplanted plants are watered until they can get their roots in the ground, it is generally not necessary to water them for the rest of their lives. We had an extreme drought in 2010 here in central Virginia and emergency water restrictions were put in place; those restrictions meant that you couldn’t water…at all. One of the reservoirs that feed our public water supply, Lake Chesdin, was all but reduced to a pond. It was truly an amazing sight to see. During that drought, guess how many times I watered, even before the emergency water restrictions were in place. Zero. Zip. Nada. I am of the mindset that my plants will either live or die trying. I don’t have the desire or time to water them regularly. So do you know what they do to compensate for my lack of interest? They send their roots further into the ground to search for their own water. For the record, I didn’t lose one plant during the drought either.

    using water wisely

    Lake Chesdin 2010 Photo courtesy of Richard MacDonald

  3. Water wisely – for those newly transplanted plants, get creative with your watering. For trees, water slowly and deeply to make sure that the rootball is being wet thoroughly. You can accomplish this in several ways. One way is by using a treegator. These are available in either donut shapes for multi-stemmed trees or upright bags that zip shut around the tree trunk. You fill them with water and the water drips out slowly and wets the rootball. If you want to make your own cheap tree gator, get a few 5-gallon buckets and drill tiny holes in the bottom. Set them around the base of the tree and fill them with water. The water will trickle out slowly and water the rootball. You can also just let the hose run at a trickle for a half hour or so at the base of the tree.using water wisely
  4. Mulch – mulching your garden will help to reduce evaporation and regulate soil temperature, both of which will reduce your plants need for water. Mulch should be applied 2″-4″ thick. If you apply it thicker, you will reduce the amount of oxygen that is penetrating into the soil and that will impair the plants’ root growth. For heaven’s sake, don’t end up with mulch volcanoes around your trees!
  5. Apply compost – this is such an important part of using water wisely. By adding compost, you are improving soil structure. By improving your soil structure, your sandy soil is able to hold more moisture and your clay soil begins to open up to allow water in. Adding compost is the magic ingredient that makes all of the other items we discussed today possible.


So what will you do in your garden to use water wisely this summer? There are many other ways to reduce your water usage and I’d love to hear what you are doing. Leave me a comment below or e-mail me at stacey@midatlanticgardening.com. Happy Friday and happy gardening!

The Vernal Equinox: It’s the First Day of Spring!


Today is the first day of spring! Woo-hoo…spring has sprung in the Mid-Atlantic gardening region. But quite honestly, we didn’t have much of a winter so we don’t really have the same enthusiasm as we had two years ago after “Snowapalooza”. But even still, it’s good to know that sustained warm temperatures are right around the corner. For those who don’t know, I’d like to quickly explain what determines our seasons on the calendar:

The Vernal Equinox – March 21 – SPRING – this is the first time in the calendar year when the hours of daylight and darkness are equal…12 hours of daylight and 12 hours of darkness.

The Summer Solstice – June 21 – SUMMER – this is the longest period of daylight in the year…from December 22 until June 21 the days get longer and longer.

The Autumnal Equinox – September 21 – AUTUMN – this is the second time in the calendar year when the hours of daylight and darkness are equal…12 hours of daylight and 12 hours of darkness.

The Winter Solstice – December 21 – WINTER – this is the shortest period of daylight in the year.

Plants are blooming like crazy now. The trees are blooming, the tulips, the forsythia, the grape hyacinths…you name it and it’s blooming. I thought that I would share a few pictures of the plants that are blooming in the central Virginia area.

Camellia (this one fell into a bed of creeping jenny)

vernal equinox

Redbud (Cercis canadensis

vernal equinox

Daphne odora

vernal equinox

Helleborus orientalis

verna; equinox

Flowering Almond (Prunus mume)

vernal equinox

I hope and pray that we don’t get a hard freeze now…that would be devastating to plants of all sorts. I remember that happening while I was a student at Virginia Tech. Trees had to have all sorts of branches removed as the freeze even killed much of the previous season’s growth. Fingers crossed that doesn’t happen this year! What’s going on in your area? What plants are blooming in your hometown? Leave me a comment below or e-mail me at stacey@midatlanticgardening.com. Happy gardening!

Reader Question: Will my daffodils be OK?


Here is a question that I received from Julia in Virginia:

My daffodil leaves are already up 6″ or so and I can see some small flower buds. I’m wondering if they will be OK with 8 weeks left in winter. It seems awfully early for them to be up.

That’s a common concern when we have temperatures that have been as mild as they have this winter. The good news is that daffodils are hard wired to survive the ups and downs of early spring weather and that’s really what we are experiencing now. If temperatures are predicted to drop into the low teens and you have either open flowers or buds that are about to open, you may want to take some measures to protect them. You can lay a lightweight cloth like a bed sheet over them or mulch over them with straw or leaves. Whatever you do, make sure that you uncover them during the day.

daffodilIf the weatherman is predicting low temperatures like I mentioned above and the buds are close to the ground or haven’t emerged at all yet, I wouldn’t do anything to protect just the foliage. The ground has an amazing insulating effect and the temperature there is generally warmer than the surrounding air in the winter. The foliage may be burned at the tips but it will still function just as it should to produce energy for next year’s flowers. A little something to remember when it comes to protecting plants from unexpected freezing temperatures: air is THE best insulator. If you are lucky enough to have snow on the ground when the temperature dips, you shouldn’t have to worry at all as snow is full of air. If you’d like to read more about bulbs of all kinds and their care be sure to check out Brent and Becky’s Bulbs. They are a Gloucester, VA based company and they have oodles of information to share…just make sure that you tell them that you heard about them on www.midatlanticgardening.com. If you have a question that you’d like to have answered, shoot me an e-mail at stacey@midatlanticgardening.com. Happy gardening!

Reader Question: Last Frost Date


Here’s a reader question that I received this week:

I’m thinking of starting my own vegetable seeds this year and I keep reading about the last frost date. I live in Northern Virginia and I’m not sure when mine is.


This question is relevant to me in so many ways. I’ll cut right to the chase for the last frost dates for the Mid-Atlantic region but then I want to expand on them a bit. The average last frost date for Zones 5-7 is somewhere between April 1 and April 30. It can vary depending on the year but this is a good baseline. In Richmond, VA I always use April 15 as the last frost date and that has served me well for years. If we were experiencing a particularly cool spring, I’d assume that closer to the end of the month would be safer. If you look at this pdf for Vienna in Northern Virginia, it shows that there is a 90% chance that freezing temperatures will occur on March 30; a 50% chance of freezing temps on April 10 and a 10% chance on April 22.

The reason that you want to know your last frost date is so that you can figure out when to start your seeds. For instance, tomatoes need to be started indoors 6-8 weeks before the last frost date. Many seed packets will say 6 weeks is sufficient but I have found that they need 8 weeks unless you’re starting them in a greenhouse. All the grow lights in the world just can’t compensate for the rays of light that emanate from that golden orb in the sky. With that being said, if you use April 15 as your last frost date, you can count backwards and see that you need to start your tomato seeds on February 19. You may be thinking that seems like forever from now but it’s only 8 weeks away. Unless you already have your seeds for next year, it’s time to get cranking on selecting which jewels you’ll have growing in your veggie garden this year. I’ve found that it takes a week to ten days to receive my seeds so that means that I need to have all of my tomato seeds ordered by February 5 and that is only 6 weeks away.

If you’ll be growing peppers in your veggie garden this year, you need to get moving even faster….those seeds need to be planted 8 to 10 weeks before the last frost date. That means they need to be planted February 5 and should be ordered by January 22. That’s exactly one month from today! I hope that you find it exciting and not overwhelming that you can start planning your vegetable garden. If you haven’t signed up for the catalogs that I mentioned in another post, I highly recommend that you do that as soon as the holidays are over. I love seeing my mailbox full of seed catalogs!

As I mentioned in yesterday’s post, I’ll be focusing on vegetable gardening for the next couple of weeks. I hope that you are excited to learn more about it…I know that I’m excited to learn more about your experiences. I’ll share successes and failures and veggies that I am in love with…there’s just a few! 🙂 Leave me a comment below or e-mail me at stacey@midatlanticgardening.com and let me know what you’re planning for your veggie garden this spring. Or perhaps you have a cool season garden in the ground right now…either way, let me know! Happy veggie gardening!

December 22, 2011Permalink 1 Comment

Did You Know? Mid-Atlantic Weather Facts


It’s Monday and that means it’s time for another “Did You Know?” post. Since the weather is finally changing here in central Virginia, I thought it would be fun to look at a few Mid-Atlantic weather facts for our region.

Did You Know that in Washington D.C.:

  • the earliest snowfall recorded fell on Oct. 5, 1892 as a trace? Or that .03 inches was recorded on October 10, 1979?
  • the latest snowfall recorded fell on May 10, 1906 as a trace? Or that 0.5 inches was recorded on  April 28, 1898?
  • the April Fools Day Storm dropped 5″ of snow on April 1, 1924?


Did You Know that in New Jersey:

  • the most snowfall ever recorded from a single event occurred in 1899 when the Great Blizzard of 1899 dropped 34″ at Cape May?
  • the Blizzard of 1996 dropped 32″ of snow at Edison, making it a close runner-up for the grand prize?


Did You Know these record low temperatures for the Mid-Atlantic region:

  • New York: -15°F on February 9, 1934 in Central Park
  • New Jersey: -34°F on January 5, 1904 in River Vale, NJ
  • Pennsylvania: -42°F on January 5, 1904 in Smethport, PA
  • Delaware: -17°F on January 17, 1893 in Millsboro, DE
  • Maryland: -40°F on January 13, 1912 in Oakland, MD
  • Washington DC: -15°F on February 11, 1999
  • West Virginia: -37°F on December 30, 1917 in Lewisburg, WV
  • Virginia: -30°F on January 25, 1985 in Giles County, VA


So when the temperatures start to drop and you start wondering just how much colder it can get, think back to these record lows…that should keep you warm for a while. Let me know how you and your plants have dealt with cold temperatures in the past. Perhaps you have a technique that you’ve used successfully in the past to overwinter tender perennials…if so, let me know at stacey@midatlanticgardening.com. I’d love to pass it along to our other gardening enthusiasts!

November 28, 2011Permalink Leave a comment