Generally organic vegetables take 2 to 4 months from planting to harvesting. This timing will vary from place to place depending on the latitude, aspect and altitude. In Summer it takes slightly less time than in Winter. Length of growing time depends a lot on temperatures.
A key to abundance when it comes to growing organic vegetables, is not how often you pick them, or how long they take to grow, but the turnaround time. The turnaround time between crops is a function of the soil fertility and can be very short.
Good soil and plenty of water, grows more nutritious and larger organic vegetables faster than poor soil. Good soil and plenty of water means that crops like kale, silver beet and rhubarb, that you can pick over a period, can be picked more often and for longer than similar crops grown in poor soil with insufficient water.
Selecting which organic vegetables to grow
Different organic vegetables have very specific requirements as regards length of daylight, maximum and minimum temperatures and water. Large commercial growers modify these limiting factors by growing in a shadehouse in summer or a hothouse in winter.
In summer and all year round in tropical areas, tomatoes, beans, capsicum, eggplant, okra, cucumbers, pumpkin, sweet potatoes and corn grow well. In winter and all year round in cool areas crops like cauliflowers, carrots, broccoli, cabbages, peas, turnips and parsnips grow well. Some crops like lettuce and silver beet do best in mid-range temperatures.
Organic vegetable crop rotation.
Some farmers leave land unplanted for a year or more and grow green cover crops like clover, which they incorporate into the soil as a green manure crop. This is a recommended strategy for conventional organic certification for growing organic vegetables. However it is possible to grow continuously in the same soil if you maintain the soil fertility and organic matter but it takes technical knowledge and skill to do this. Ideally the type of crop grown in the one area is changed after each harvest so that you grow tubers like potato and then switch to a leafy crop.
Seeds: hybrid and heirloom
Hybrid seeds have been developed by seed companies to maximise production and to develop certain characteristics. Hybrid beans, for example, have been developed so that all the beans develop at the same time so that they can be harvested by machine, which pulls up the plants and separates the beans.
Hybrid plants do not produce viable seeds. Production of most commercial seeds is controlled by the big six food multinational companies. Monsanto, Syngenta, Dupont, Mitsui, Aventis and Dow now control 98% of the world’s seed sales. They invest heavily in research the purpose of which is to increase food production capacity and make vegetables easier to transport.
With the development of food crops which contain “terminator” genes, there is a groundswell towards “heirloom varieties” and a movement towards protecting seeds. In the USA the Seed Savers Exchange and publishes an annual yearbook with over 12,000 the seed varieties cultivated by members (www.seedsavers.org).
Organic vegetable crops are not all propagated by seed. Potatoes grow from tubers. Artichokes, ginger and sweet potatoes grow from root sections. Asparagus, rhubarb and various oriental or asian vegetables grow from crowns.
For some organic vegetables you plant seeds straight into the ground. Others are best transplanted, after being initially established in trays. Those that are generally seeded directly into the ground are carrots, onions, beetroot, turnips, shallots, parsnips, sweet corn, pumpkins, peas and beans. Whereas cabbage, cauliflowers, broccoli, silver beet, celery and leeks are generally transplanted.
Successful establishment by direct seeding depends on two factors:
the ability to place the seed in the right place and quantities—either by hand or machine.
optimal seedbed preparation.
Our seedbed preparation involves mounding, loosening the soil with a garden fork and fertilising. We use a “no dig” approach as we believe digging and ploughing upset and sometimes kill the soil organisms that are essential for a healthy soil.
The advantages of transplanting are:
It shortens the growing season thus permitting more efficient use of organic vegetable growing land.
Improves crop uniformity.
Permits more accurate prediction of harvesting dates.
Eliminates the time & cost of thinning.
Permits greater control of early growth and development.
Allows culling of seedlings showing poor growth and vigour.
Disadvantages of transplants compared to direct seeding:
Cost per seedling may be too great where a large number are required; extra labour in establishing the crop.
Can damage the tap root.
If transplants are delayed from planting out (due to adverse weather or delays in land preparation), yields may decline and maturity is delayed.
So which are the most profitable organic vegetables?
Organic vegetables are quick-growing high return crops. You can produce very high yields of celery and tomatoes in a small space so these can be very profitable.
It is not obvious which organic vegetables are most profitable as many factors come into play. We have a standard row length which is about 20 metres. Broccoli yields about $300 + per row. Carrots yield about $600+ per row. Kale gets $330 per row but you can pick at least four times from the same row, so is highly profitable if you can sell it. Fortunately for us we found a large customer who loves kale, because our local farmers’ market sells only a few bunches a week. Peas and beans both take a long time to pick but both get several picks; peas fetch a better price than beans, but beans are more prolific.
Some other factors that affect profitability are density of planting and the ability to pick several times from the one plant. On this latter factor rhubarb scores best, followed by kale and silver beet. Peas and beans also pick several times. In addition, two other considerations are whether they are easy to grow (like silver beet) and easy to pick and pack. Some organic vegetables take a lot more labour e.g. in small quantities carrots and potatoes need washing which can be time consuming. When grown in bigger volume you can automate both the picking and packing and washing of carrots and potatoes.
Your profitability can also be affected by what other growers do. This is the competition factor and locally if two or three other growers focus on growing large quantities of one particular crop this can adversely affect your sales.
So what are the top selling organic vegetables?
Market acceptance is one of the key factors to take into account. The organic vegetables that sell best at our local farmers’ market are:
Potatoes, Tomatoes, Carrots, Onions, Lettuce, Pumpkins, Runner Beans, Sweet Corn, Peas, Cauliflowers, Broccoli, Red capsicum, Silver Beet and Asparagus.
Other aspects of growing organic vegetables are: