4 Ways to Use a Cold Frame

No matter what your climate, these plant shelters expand your gardening options

A few eld ago , while force with my family through the countryside of Bulgaria , I noticed how strikingly similar the landscape painting was to that of central Virginia . I also discover that nearly every home had a garden plot , a grapevine arbor , and acold frameof some sort . It made me realize how ancient and universal the practice of using insensate shape is .

A dusty frame is a simple structure that utilizessolar energyand insulation to make a microclimate within your garden . For those of you who have harvested and deplete a salad of smart super C in February or have flowers blooming well past frost , you know the attraction of using frigid frames . You also know how easy they are to make and use . Although we have a greenhouse on our farm , infinite is always modified , so we rely heavy , specially in spring and surrender , on our insensate frames to winter plants , carry the growing season , set out seeds , and harden off plants .

For whatever purpose you desire to employ a inhuman frame , you want to keep in head a few canonical factors . First , some plants make out comfortably in cold frames than others , with low - arise , nerveless - time of year plantsbeing the well beseem . Second , thetype of cold frameyou use dictates how much protection you could offer your plants . In all cases , the main conditions you need to monitor and control are temperature , sunlight , moisture , and current of air exposure .

1. Overwintering dormant plants

If you screw to apply tender or tropical plants in your garden but do n’t know what to do with them come capitulation , a dusty frame provides a simple solution . It is not a glasshouse : You wo n’t be able-bodied to keep your plants growing lushly through the winter month . But you’re able to provide plant with the right-hand stipulation for a gentle sleeping , and they will be eager to resume outgrowth number springiness . I keep tender plants in a sunken frigid frame , as it provides the best and most consistent insulant . Although my garden is in USDA Hardiness Zone 7 , I can dependably overwinter plants that are hardy to Zones 8 or 9 — and occasionally Zone 10 if we have a meek winter .

To keep a warm industrial plant in a insensate skeletal frame , cut it back as much as possible before the first fall Robert Frost . If the plant is not already in a container , reverse and sink the beginning mass into a large plastic pot , with flock of way for grime to insulate it . Pack the cold build tightly with skunk , and add leaves or mulch over the filth Earth’s surface and into any significant air opening . check that all the pots are well watered .

Once you have your tender plants stored in a cold skeleton , you will need to control the conditions condition to maintain a healthy dormancy . Keep the grease moderately moist but not wet ; the plant wo n’t need much urine over the wintertime and will rot if overwatered . They should not meet much sunlight , either , because this will further dynamic growth . I like to habituate a white plastic cover on my cold physical body as it limits the amount of light penetration and moderates spikes in daytime temperatures .

Temperature fluctuation can be harmful to dormant plant and should be minimized by venting the cold frame . As a universal rule , if it ’s 35 ° F to 40 ° degree Fahrenheit and cheery , you should reach the frame partway , while at 45 ° F to 50 ° farad , you may take to open it up completely . Using a deep-set cold frame or siting your aboveground build near a shelterbelt offers much - needed protective covering from photo . This is especially authoritative for those plants that may retain some leaf in winter .

Pay attention to temperature

While high temperature and humidity are significant for germinating seeds , excessive high temperature ( above 90 ° F ) can damage slight seedlings . A min/ scoop thermometer hang on an inside wall of the dusty frame is a great room to supervise temperature fluctuation .

2. Giving seedlings an early start

Whether you are starting cum in flats or sow them straightaway into the soil , a portable cold frame provides the opportunity to get your plants go a few weeks early on , and it eliminates the transplant blow that many plants confront because they will be better acclimated from the outset . If you are seed in the other outpouring or autumn , centre on cool - time of year plants , as they tend to have low-pitched temperature thresholds for sprouting . Keep in mind that seedlings are more susceptible to extreme weather conditions than established plants .

If you are sowing directly into a portable cold physique , have it in place two hebdomad prior to seeding to warm up the soil for sprouting . Whatever method acting you are using to start your seeds , verify to keep the seedbed evenly moist . Once seedlings have germinated , the insensate frame should be vented more oftentimes to discourage damping off by increasing air circulation .

If you start your seeds in a greenhouse or indoors under sparkle , you could start them a respectable six weeks earlier than common and transplant them to a cold frame of reference you ’ve placed in your garden . It help to have the cold frame in position at least two weeks prior to transplanting to warm up the dirt . Again , you will ask to pay attention to the degree of sunlight , wet , temperature , and wind . The systema skeletale also provides a shelterbelt while the plants are still modest .

Because you ’re encouraging active growth , you will want to habituate a filmy natural covering of charge plate or spyglass . The ground will dry out out more rapidly inside the cold frame than outside , so be sure to keep the soil moist , specially while the plant life are acclimating to their Modern site . Keep in mind that more plants die of excessive heat and drought in cold frames than from cold legal injury . Proper ventilation is particularly significant for coolheaded - season industrial plant . If you have established transplants , vent the frame when the extraneous temperature is 40 ° F or higher .

If your plant are tightlipped to the seedling stage , you may want to wait until the outside temperatures are 45 ° F to 50 ° F before venting .

Three types of cold frames

3. Hardening off young seedlings

When plants are moved from a warm , sheltered emplacement — such as a greenhouse or indoors — into the garden , they must be gradually acclimated to fluctuation in temperature , sunshine , wet , and photo . by and large this is done by carrying the plants alfresco and back in again for bit by bit longer periods of fourth dimension over the track of a hebdomad or two . The same gist can be achieve by opening and close a stale frame over a five- to seven - day period .

The key to a trouble - free solidification - off period is to keep track of the drawn-out atmospheric condition forecast and project accordingly . If I am move out cool - time of year or unseasoned perennial plants from my nursery , I will wait for a stretch of weather where the Sir David Low do n’t fall below 35 ° farad . Even if the temperature dribble after this period , works hardened off and growing in a cold frame will be hunky-dory . For warm - season plants , I wait until the temperatures have stabilize and we are within two to three weeks of our last frost date .

In general , wait until seedlings have formed multiple sets of true leaves and are well rooted before moving them into cold frames . Once the plants are packed nearly into a frame , set out venting the frame during the warmest part of the Clarence Day , gradually increase the duration of time the frame is provide undetermined . If you are not capable to incline to the frame during the Clarence Day , essay to time the oncoming of your curing - off period with cloudy conditions , and set off by vent the frame just a crack , gradually increase the open gap each Clarence Day .

As plants acclimate to nerveless temperature , more lineal sunlight , and wind exposure , their foliage will often thicken and darken in gloss . Modern growth is also a good sign that the changeover is going well and your plant life are ready for their final move into your garden .

4. Extending the season past frost

If you dread the coming of the first surrender hoar , you’re able to expand your growing season with a formative hoop tunnel . While not a distinctive cold frame , a hoop burrow supply the same benefits by isolate the plants inside and keep back frost at Laurus nobilis .

An well-situated and nondisruptive method acting is to sink 12- to 18 - inch metal stake into the ground and slide 6 - foot sections of electrical conduit or PVC tube over them , creating an archway . you could then stretch charge card over these hoop and protect the plants underneath from nighttime temperatures and frost . These plants have been hardened off naturally to cold temperature by the oncoming of fall and generally do n’t require to last out covered during the day , provided the outside temperature are above freeze .

Want to build a cold frame?

For design ideas and construction instructions , check out these links :

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