I have yellow needles on sago plant.
This article will help you:
https://www.gardeningknowhow.com/plant-problems/environmental/plant-leaves-turn-yellow.htm
I have Sago Palm food 12-4-12, and it does not say whether you use it in its dry state (sprinkling it about the base and then watering it in?) or do you dilute it in water and water the plant with it?
I would simply mix it with water and feed the plants during watering. You can dilute it if desired, depending on the label instructions.
I have several sagos in my yard. We live in Houston. They are large and mature and always have grown well. BUT one of them now has a big ball in the center and it appears to be undeveloped leaves. The rest of the plant is turning yellow and is not healthy looking. Should I cut out the ball in the center? The plant is about 4 1/2 ft. tall and the ball in the center is a bit smaller than a basketball- about the size of a soccer ball.
It sounds like it may be flowering. This website can help you with information on that: http://www.rhapisgardens.com/sagos/sagoseed.htm
Do not cut it out, it will damage the plant.
I have a sago and it had a big brown dome in the center and some new blooms came out of it. There are some red bulbs attached to the dome that opened up for the new bloom. I have several of these plants but none have ever had this type of center. My question is, what is the dome on this sago?
This is the reproductive organ of the sago. Cone-shaped protrusions are normally male while females have a more cabbage-like appearance. Here is more information: https://www.gardeningknowhow.com/ornamental/trees/sago-palm/sago-palms-flower.htm
My sago has white things (about 1 mm, less than 1/16 in.that look like dashes - - - - ) covering the leaves, bottom and top, and in some areas on the stems of leaves. In some places they are mixed in with tan/brown material, forming a covering that is so complete you cannot see the green leaf stem unless you brush it off with your finger. Is this your typical scale that needs to be treated with an oil? Should all the leaves be cut off, including baby ones coming out of the ground (which also have these white line things)?
It does sound like it is scale. Treat the leaves and leave them on the tree. While they may look unsightly until new leaves grow in, the plant needs them to help it remain healthy and to produce energy while it is growing new leaves. This article will help you with the scale: https://www.gardeningknowhow.com/houseplants/palms/sticky-palm-tree-leaves-treatment-for-palm-scale.htm
A new spring small Sago has turned yellow. After reading the articles available, I know it is a nutrient deficiency and possibly I let it get too dry in the summer. It is in the clay 4-inch pot that it came in. I'd like to know a good fertilizer and soil for the transplanting. It will be in the house.
Fertilizing with a slow-release, balanced tropical fertilizer with micro-elements will usually suffice.
I have sago that grew a long bright yellow, soft cone in the center. I broke it off. A couple months later new spears stated growing two separate sets of new shoots in center. Is this normal?
Yes, this is normal. This is generally where the reporductive organs are located--males will produce cone-shaped growths, while females look more like cabbages. Cutting them off will not affect the plants.