What kind of soil and climate does it take to grow sweet potatoes, and can I grow them in any part of Contra Costa county, and about what time is the best to plant them?

Sweet potatoes do best in a light warm loam which drains well and does not bake or crust by rain or irrigation.  Sprout the tubers in a hot-bed or cold-frame in February and break off the shoots and plant as soon as you are out of danger by frost.  Sweet potatoes are more tender than common potatoes.  There are places in Contra Costa county where they do well, though some parts of the county do not have enough summer heat.

Sweet Potatoes Between Fruit Trees.

I am expecting to grow a fall crop of about twenty acres of sweet potatoes.  The land is a heavy, sandy loam in the interior, which has been set out this spring to almonds, apricots and prunes.  I wish to grow sweet potatoes between trees.  Would an irrigation every forty days be often enough?  Also, if either sweet or Irish potatoes grown between rows are harmful to either of the varieties of fruit mentioned?

We see no reason why you should not get your crop, providing you do not have to run the plants into the frosty period, and sweet potatoes will not, of course, stand frost as well as the common potato.  The moisture which you propose to give ought to be enough for a retentive soil in connection with good cultivation until the vines cover the ground.  Growing any crop between orchard trees is apt to be an injury to the trees, because of the spaces which are not and cannot be adequately cultivated, so that the ground around the trees is apt to become compacted either by the run of water or the lack of cultivation, or both.  Our observation has been that Irish potatoes are no more injurious than other crops.  Any crop will injure young trees if it takes moisture they ought to have or interferes with good cultivation of the land.

Giant Japanese Radish.

In discussing sakurajima (giant Japanese radish) Eastern publications advise planting late, about August 1, and not earlier than July 1.  What can you tell me about the plant here?

The Asiatic winter radishes can be successfully planted in California in July or August if the soil is thoroughly saturated by irrigation before digging and planting.  It is, however, not so necessary to begin early in California as at the East, because our winter temperatures favor the growth of the plant, while at the East they have to make an early start in order to get something well grown before the ground freezes.  For the growth of winter radishes, then, in California you can wait until the ground is wet thoroughly by the rain, which may be expected during September, and afterward you can make later plantings for succession at any time you desire during the rainy season.  This applies to all kinds of radishes.

Rhubarb Rotting.

I have planted rhubarb roots in the San Joaquin valley and find the root crowns rot below the surface.