Saturday 31 March 2007

March Weather

The weather for March was mild and sunny but with a lot of frosty nights, and very little rain towards the end of the month.

Only 39mm of rain fell this month (Dublin Airport conditions 16km away), we would normally expect to get in the region of 53.5mm, but most of it in the first three weeks. The mean air and soil temperatures for the month were about normal at 6.4 degrees C and 6.2 degrees C respectively. The total amount of solar radiation for the month (intensity of energy from the sun including overcast days) was slightly higher than normal (26680 Joules/sqcm). These average monthly conditions hide fact that the first half of the month was wetter and cloudier and the last 12 days were drier and sunnier than normal.

In the temperature charts above (extracted from the Met √Čireann summary) the maximum temperature for Dublin area (blue line) dropped considerably from the 18th to the 21st when all of the precipitation was snow or hail, and there was ground frosts at night throughout the month.

These charts show how little rain came in the latter part of the month and that we only had 4 days where there was more than a light drizzle of rain (blue bars), not enough to really soak into the ground.

Sunday 25 March 2007

Week 12 - Bed 8 Planting

This bed had been prepared the previous week as a single-dig bed, and in the south quarter of the bed we sowed:

  • Meteor Dwarf Peas (4 short rows) - an early hardy variety ideal for both autumn and spring sowing, grows to 35cm high
One row of the pea seeds came straight from the packet, while three rows were sown from seed that had been pre-sprouted, a method of ensuring higher germination rates in the cold soil of the spring. Unfortunately the roots of the peas had grown more than they should have, they should have been planted two or three days earlier, and any advantage from the pre-sprouting was probably reduced by the stress on the extended root.
The peas were planted in this bed by mistake - we had planned to plant them into Bed 5 beside the potatoes and broad beans.

Week 12 - Bed 5 Planting

We prepared this bed as a lazy bed, which involved cutting out a piece of sod with as much topsoil as remained attached, and turning it upside-down. The surface of the bed was then worked over with a sharp spade to break up the clods slightly. In this roughly prepared bed we planted:

  • Express Broad Bean (4 short rows) - a fast maturing longpod variety growing 60cm tall
  • Orla Potatoes (21 sets) - a 1st early variety with creamy white oval tubers with light yellow flesh

Sunday 18 March 2007

Week 11 - Planting

We we prepared some small pots of seed compost, and sowed 6 different varieties of tomatoes, 6-8 seeds in each pot:

  • Stupice Tomato - early ripening variety with abundant medium size tangy red fruit, grows and ripens well outdoors
  • Brandywine Tomato - an Amish heritage variety with large pink fruits that are late maturing
  • Gardeners Delight - red cherry variety with abundant long trusses, suitable for indoor or outdoor use
  • Matina - very early cropping, medium sized bright red variety with a delicious taste
  • Golden Peacevine - a variety with long sprays of small sweet golden plumb shaped tomatoes, fairly productive outdoors
  • San Marzano - red plum variety for cooking and bottling, best grown under cover
Each of these tomatoes is a cordon variety (tall) and will be potted up in to larger separate pots later in the spring.

We also planted two pots with onion seeds, approximately 60 seeds in each pot:
  • Baun Onion - a large, white, strong bulb excellent keeping variety
  • James Long Keeping Onion - an old english variety, with medium sized reddish brown bulb
All of the pots were covered with plastic to keep in the moisture until they germinated and were put on a sunny windowsill.

Sunday 11 March 2007

Week 10 - Soil Analysis

We dug a pit almost 1 meter deep in order to examine the nature of the soil in the garden (or at least one section of it).

The nature of the layers of the soil is an important factor in the productivity of the garden, as is the ratio of sand/silt/clay in each layer. Through digging we found 4 distinct layers of soil:

About 30cm of topsoil containing a fair amount of stones.

About 40cm of soil that contained less stones and was lighter in colour.

A 20cm layer of rubble containing a lot of shells.

The subsoil started about 90cm down.

The soil in this back garden was probably brought in from elsewhere, being so close to the canal and as indicated by the presence of a shell and stone layer, and it is possible that if we kept digging we would find additional layers.

We took samples of the topsoil, mid-soil and sub-soil, removed all of the stones and roots did a fractional soil analysis test on each of the three samples. We also did the test on a sample of clay soil from Bruce's allotment. The test involved filling a jar half full of the soil, then filling it it up with water to within a few centimeters of the rim. Once the lids were sealed we shook up the jars vigorously for 5 minutes to break up all of the soil clumps and then placed them on the table.

The sand settled out of the mixture first, generally within a minute, then the silt settled over the next hour, and finally the smallest particles of clay settled out of the water over the next couple of days/weeks

This photo was taken after one hour of settling, and shows (from left to right) the sub-soil, the mid-soil, the topsoil and the soil from another site. It is difficult to see the layers of sediment with these photographs.

The sample of the topsoil settled fairy quickly and the water at the top became almost clear within the hour - indicating that there is almost no clay in the sample. It was difficult to locate the separation between sand and silt as it is such a gradual transition, but there seems to be about 60-70% silt and 30-40% sand.

The sample of soil taken below the topsoil is easier to read. Again the water became quite clear fairly quickly, and very little clay settled out - (a thin lighter line of clay is visible on top of the silt). In the photograph above, there is a red line drawn on the tape indicating the approximate division between sand on the bottom and silt on the top, with about 60% silt and 40% sand.

This sample is of the subsoil again shows almost no clay (the water is fairly clear after one hour) and only about 25% sand as seen by the faint red line.

This soil would be classified as a silt-loam with a medium texture. This soil is fairly free draining, but may not be capable of holding on to nutrients because of the lack of clay and soil humus, both of which operates almost like a magnet to attract and hold onto nutrients.

In comparison, with the soil sample taken from the clay topsoil of Bruce's allotment, it is impossible to see any layering of the soil, and it will end up taking a week or more before the clay settles out of the water. This sample eventually showed over 50% clay with about 25% each of silt and fine sand. This soil is fairly fertile but difficult to manage.