Gardening Pleasures

Posts Tagged ‘humidity’

Seeds

Starting annuals and vegetables from seed can be rewarding or disastrous depending upon the outcome.

Many people start seeds too early and then try to hold the seedlings  back until it is warm enough to plant them outdoors.  Starting them too early can  result in either yellow seedlings that are short and hard and grow very slowly or spindly ones that grow too tall and topple over.  Neither will do well when planted outdoors.

 

Conditions: Seeds require certain conditions to germinate and grow properly.  These include temperature, light and humidity.  Also, good sanitary practices must be followed so as to reduce problems with diseases.

 

Germination media:  Soil mixtures such as a 3-2-1 or 2-1-1 or even a 1-1-1 (soil, peat and sand) can be used to start seeds.  However the mix must be treated to reduce disease problems.  Treatment can be with heat or the chemical methyl bromide.  On a smaller scale, heating a 2-3 inch layer of mix in a preheated oven at 180ºF (82ºC) for one hour will pasteurize it.  To avoid using chemicals or heat, purchase an appropriate ready mixed compost designed specially for seeds.

 

Containers:  Anything that will hold about 2″ (5cm) of the media, with drainage holes in the bottom can be used to start seeds.  Fill the containers with the moistened mix, firm down lightly and label.

Seeds:  Use only the best seeds.  Old seeds or those that have not be stored properly may not germinate.  If extra seeds are to be stored from one year to the next, keep them at 40-50ºF (5-10ºC) in an air tight container such as a coffee jar. The humidity should also be kept below 50%, an average home fridge will do the job.

Many people tend to sow seeds too thickly.  Home gardeners should sow seeds about ¼ inch (0.6cm) apart and in rows.  Cover large seeds lightly with  the soil mix, washed sand or vermiculite.  Leave small seeds uncovered.  If seeds are sown too thickly, tall spindly seedlings may result.

 

Water and humidity:  After sowing and covering, water the seeds well.  Do this with a fine mist or sub-irrigation so that the seeds will not be washed away. After watering try to keep the humidity at 80% or higher.  This will reduce water loss from the germinating media.

Some growers cover the seed flats with wet burlap, clear plastic, or newspapers.  Home gardeners may slip the seed flats into large clear plastic bags.  Place in light but not direct sunlight.  Do not let the temperature in the plastic bag go above 85ºF (29ºC).  Check the flats daily to make sure the  surface of the soil is moist. As soon as seedlings emerge, remove the plastic bag.

 

Temperature:  This is one of the most critical factors in starting seeds.  Temperature that is too low or too high will reduce or stop germination.  Bottom heat from electric cables, hot pipes or radiators may assist in maintaining proper temperature.  The temperature required is of the growing media not the air.

 

Light:  Some annual and vegetable seeds require light to germinate.  Place seed flats where some light is available.  After seedlings emerge, provide full sunlight or, if not possible, use fluorescent lights and supply about 27 lamp watts per square foot.  Containers with the seedlings should be placed 8 inches  (20cm) below the lamps.  A 14 hour day should be provided, usually 8am to10pm. Transplant seedlings when the true leaves appear.

 

Hardening-off:  About 7-10 days before plants are to be planted outside, the plants may be hardened-off.  This is done by lowering the temperature by moving them outside during the day and back in again at night or withholding water.  During this period the plants should be in full sunlight. Do not harden off cucumbers, melons or squash.

Building your own small greenhouse can be an enjoyable and economical especially if you are clever with tools. Select well-drained and level ground for your greenhouse. If you will be using it mainly in summer for plant propagation, it can be situated in partial shade to reduce heat buildup.

The north side of your garden, with some shade from a tree is an ideal location. If there is no partly or moderately shady area available, you can use white paint or shade cloth on the inside ceiling to regulate the amount of sunlight that comes into the interior of  your greenhouse.

If you will be using the greenhouse for young transplants or growing plants on to maturity and fruiting, your greenhouse should be put up in an area with the highest sun exposure available in your garden. Also, situate it where there is good air flow and reasonable water drainage. Do not construct your greenhouse in low lying areas surrounded by tall buildings or woods.  When deciding where to put the greenhouse be sure to consider how convenient the access to water and electricity is going to be.

Take into consideration the time you have for working in your greenhouse when choosing the kind of greenhouse you want and how big it is going to be. Although it’s not true that a greenhouse requires continuous attention, don’t be overly ambitious and buy something that will be more than you want to handle.  New owners of greenhouses often think they will spend far more time there than they actually can or that the greenhouse will not require as much maintenance as they do.

The greenhouse environment can be sustained often with minimal maintenance if using automated controls that operate the ventilation, heating, humidity, artificial lighting and watering. If, however, you don’t want (or can’t afford) to install an automated control system, begin with plants that don’t require specialist care.

There are many prefabricated greenhouses on the market or you can build one by using simple frames. For safety sake, make sure that a certified plumber and electrician installs any automated systems.

Greenhouse kits are widely available in various materials, styles and price ranges. Be sure to check with the local planning department if the greenhouse you choose requires planning consent.  Most won’t, but a really large one situated next to your neighbour’s kitchen window just might. Better safe than sorry.

If you are an avid DIY’er, your new greenhouse can be constructed for a relatively small outlay of cash.  A lean-to greenhouse can be built against a garage or a house, thereby taking advantage of the existing wall, but don’t forget to consider head room and sitting space.

There are some major advantages to purchasing a greenhouse kit. Details like humidity, ventilation and leakage have already been dealt with in the design. Whereas someone constructing the greenhouse from scratch must remember to consider all elements just to avoid problems in the future that could result in the greenhouse not functioning as it should.

Here are some tips to help you design and build your own small greenhouse:

1.  Begin with a design that uses materials that are readily available. Attractive greenhouses can be constructed using recycled materials such single glazed windows or reused lumber.

2.  Adapt the design to accommodate the climate in your area so you won’t have to make further adjustments later.

3. Use a design that makes use of standard-sized building materials. Specialist sizes always cost more.

4.  When planning the design of your greenhouse, take into account the type of gardening you enjoy and plan to do.  Growing rare specimen plants or hydroponic gardening is very different from growing the run of the mill vegetables and flowers for the garden.

5.  Considering the climate in your area, plan into the design any timers and thermostats needed to regulate the precise levels of heat or light you want for the plants you will be growing.

6.  Design and implement a back-up arrangement for operating heating or lighting equipment in case of power failures or extreme weather conditions.

7.  If you are building a wooden greenhouse, you can use cedar, redwood or cypress, but remember that you will have to regularly treat or paint the wood. For cost-effectiveness and economy, use pressure treated wood for the framing.

8.  Greenhouses often have glass panes installed, but polycarbonate plastic, fiberglass, plastic film or acrylic panes or sheets can also be used.

Greenhouses have come a long way over the past ten years both in terms of price and materials used.  A greenhouse is vital to a keen gardener for extending the growing season and the types of plants they can grow.