Grow me, grow me! Hen and chicks
Some of you have probably seen the cute kitten or puppy videos on YouTube, or perhaps even stumbled upon a show or channel on cable that focuses on these cute little fur balls. I love cute little kittens and puppies as much as most people, but after an hour or two, that is about as much as I can take for a while. How about a new show or even a short video dedicated to cute plants? When I think of cute plants, one of the first ones that comes to mind are hen and chicks (Sempervivum). I thought about this yesterday when I was planting some new, and very cute little guys, in the Rock Garden at McCrory Gardens. Hen and chick plants are cute for a number of reasons. First of all they are rather small, usually only growing a few inches tall, unless they are in bloom at the time. Secondly, they produce offsets that develop around the outside of the plant, giving the appearance of a hen with her little chicks surrounding her. Pretty cute, even for most kids that may never have lived on a farm or even seen a mother hen and how she will gather her chicks around herself and cover them with her wings for protection. These plants can also grow just about anywhere, often in what look like pretty inhospitable locations like in the crevices of rocks. They grow well in containers of all sorts too. Got an old blown out tennis shoe or boot, fill it with potting soil and stick a plant in it! They are a great plant for kids to get involved in gardening and fun to share with your friends.
The botanical name for Hen and chicks is Sempervivum, which means always alive, derived from the fact that these plants are evergreen, even here in the Northern Great Plains. Like some other hardy succulents such as Opuntia, the plants self-desiccate, reducing the amount of water in their leaves and thereby increasing the concentration of salts in the plant sap to provide a sort of plant anti-freeze to get through the winter. Granted the leaves will look pretty limp come spring, but they usually plump back up and the plants start growing as soon as the weather starts to warm up. Sometimes you will also see another common name for Sempervivum (“Semps” for short) is houseleek. This is derived from the old practice of planting them on the thatched roof of their home for good luck, particularly in warding off lightening strikes. Hen and chick plants will probably not survive on a typical house roof today, unless you happen to have a green or living roof, like we see becoming more popular in many cities and especially in Europe. We have a living roof on the Straw Bale house at McCrory Gardens but do not have any hen and chick plants growing on it, just sedums. But, since many Sempervivum species and selections are extremely hardy, often down to Zone 3, we should give them a try!
Sempervivum come in quite a variety, with about 40 different species and probably hundreds of cultivars. Generally the plants are mostly green, tinged in red or mostly reddish green. Some, like S. arachnoideum, have an interesting web-like growth of hairs across the top of the plant. Semps grow best in full sun but can also take some shade. Flower stalks may appear in July, sometimes growing up to a foot tall. The flowers are interesting, usually dark pink or purple, but are not really that pretty. Once the flower fades, that plant will also fade and die but don’t worry, the “chicks” will carry on. Well-grown plants can form colonies a foot wide or more. They are often grown in rock gardens since they can tolerate heat and drought once established.
Do You Need to Water?
Now that it is July and the heavy rains of June are over, it might be time to think about getting out the hose and start watering the lawn, garden and newly planted trees and shrubs. Generally, plants need about 1” of water per week to maintain good growth and avoid stress. This water can come from natural rainfall or from irrigations. Normally rainfall in July is pretty scattered, coming mostly from thunderstorms that might drop an inch or more in one spot while nearly missing another area a short distance away. Day-long, soaking rains can occur but are less common.
If garden plants like tomatoes get stressed because of a lack of water, they are more likely to have lower yields and physiological disorders like blossom-end rot. Water stress can also cause plants to drop leaves, flowers or even young, developing fruit. Plants in containers are particularly prone to water stress because the plants’ roots are restricted to the container and cannot grow out to harvest water farther out. Young trees and shrubs that were planted this spring need to be watched carefully for water stress because they may die this summer or may be weakened so that they do not make it through the winter.
So when should you water a plant or a garden? There are a few basic guidelines. First, do not water until the plant needs it. Water thoroughly, then do not water again until the plant needs it. Proper watering is a skill that few people actually have. If you watch television, particularly commercials, you would think that you just stand there with the hose and sprinkle the tops of the plants with water. The tops of the plants do not need the water, the roots do! It would be much better to use a hose with a breaker on the end that slows the water down to a nice soft sprinkle then water the plants at the base, keeping the foliage dry. Unfortunately most of the plant watering nozzles or heads only have a few holes so that the water comes out with lots of force which can wash out soil or even knock plants over. My favorite watering head is about 3” in diameter and has 1000 tiny holes that really softens the blow of the water on the soil. Sadly, a good quality watering wand with a head like that is seldom available to the average gardener. Ooze hoses, drip lines and similar low-water using irrigation methods work well too. They keep the foliage dry, which reduces disease problems and also save water. They work great in vegetable gardens and flower beds too.
How do you know when a plant needs water? Wilting is the most common symptom that signifies that a plant needs water. But, once a plant is wilted, it has already been stressed out to the point where permanent plant damage has occurred. So, the trick is to water right before the plant is really stressed or just shows the very first signs of wilting. In many plants the leaves will take on a grayish cast or have a duller appearance. It takes some time to learn to recognize this but once you do it can be spotted from some distance away. The other way to check is to stick your finger into the soil or use a trowel to dig down and see if the soil is moist or getting dry. Moist soil will feel cooler and have a darker color than dry soil. Small pots can also be picked up to check their weight. Wet media is heavier than dry media so learn how much a well watered plant feels versus a plant that needs to be watered.
Watering thoroughly is the next aspect of proper watering. If you are watering plants in a container, add enough water so that the excess water drains out of the bottom of the container. If the media in the container got really dry, you might have to water the container a few times to really get the media saturated. If you are watering a tree or shrub, water near the main stem but also water out around the edge of where the root ball would be. New roots should develop on the plant after planting. Those roots should extend out from the original planting hole so give them some water too. Usually a few gallons of water per young tree, once a week, should be good. If you are watering in your garden, remember to shoot for that 1” of water per week. Put out some empty tin cans or other containers to catch water from overhead sprinklers then keep them on until you have about an inch of water captured in the cans. You can also dig down with the trowel to see how far the water has soaked in. Try to saturate the top 6-8” of soil when watering.
Frequency of watering will depend on what you are watering. A container with lots of plants growing in it might need watering twice a day during the heat of the summer, particularly if it is in a sunny or warm location. Smaller houseplants in your home may not need water more than once a week depending on the kind of plant and how much it is growing. Gardens will usually need water once a week if they do not get that 1” of rainfall naturally.
One last note to remember, overwatering is a very common killer of plants, particularly houseplants. The excess rainfall that many areas received in June could also have damaged roots, decreasing the plant’s ability to take up water, causing it to wilt. In some cases, a thorough watering might be the last thing that plant needs. Check the soil to see if it is dry before watering.
A Few Questions from eXtension Ask-An-Expert
Client stopped in with a tomato sample. They first noticed the problem about 2 weeks ago. They water from the bottom, fertilized and used a fungicide on the plants. They are Early Girls brand. Please ID and recommend treatment options. They were given a copy of the Iowa tomato treatment and diseases brochure.
This looks like Septoria leaf spot on the tomatoes, a fairly common leaf disease, especially during wet weather like we have had the last few weeks and this spring. It sounds like you are doing the right thing with watering from below and using a fungicide, which usually helps but the excessively wet weather this year has been a real problem. Do you rotate where you plant your tomatoes? Do you stake or cage them to keep them up off the ground? Mulching around the plants can also help reduce disease problems like this since the spores are splashed up from the soil during rains, covering it with mulch helps reduce that problem. I would continue the fungicide sprays, using one that has chlorothalonil in it.
Hi I am in Vermillion SD I have little Elm trees (maybe 2’ tall) and maybe some other type of trees taking over taking over my juniper bushes and daylilies. How can I get rid of the pesky trees without hurting the other stuff? Any suggestions would be much appreciated.
Probably the best thing to do is try to dig them out. If you can get in close to the base of the little tree and dig down, you should be able to loosen or cut the roots and then pull it out. You might be able to just pull some of them out, particularly after a rain when the soil is moist, but elms can be tough to pull out without cutting the roots or loosening up the root from the soil. If you just cut them off they will just grow back and be even harder to remove next year. I would not recommend using any spray in amongst your perennials.
Save the Date!
Even though summer started somewhat late this year it is time to mark your calendars for the Annual McCrory Garden Party. A reminder that the date has moved from the third Friday in August to August 1st. It will still be the same wonderful summer event as it has been in the past, just a bit earlier. During the first part of August the Gardens should be in full bloom for guests to enjoy. It will be the perfect opportunity to meet old friends and exchange news and gardening ideas while listening to some great music by a local jazz band “Murph and Friends”. For the folks who had not been to the new Education and Visitor Center, it is a perfect evening to wander through the new facility enjoying an SDSU ice cream cone.
We will spray for mosquitoes but it would still be a good idea to bring your own repellant and a long sleeved shirt. Hope to see you on August 1. Contact us at 605-688-6707 or go to our website www.mccrorygardens.com for more information.