I have planted a Bilva (Bel) plant in my lawn whose leaves I use for Shiva pooja. Some of the priests said that Bel plant should not be planted in the house. Instead, it should be migrated to a temple.
Is it true?
Bilva tree is not normal tree. There are many Bilva trees in many jungles of India. There is no restriction that Bilva tree can not be planted at home. In hinduism, each home is a symbol of Shivalaya. Each father is a symbol of Shiva, Every mother is considered as pious and pure and respected as mother Parvati.
Blva tree is having pure effects. Many people just go to temple and put Bilva leaf on Shivalinga and just go out of temple. It is not true ritual.
is touch Bilva leaf to ShivaLingam , chant "Bilvashatak verses"
Tridalam Trigunakaam, Trinetram cha triyayudham,
Trijanma pap samharama Ek bilvam shivarpanam
You can chant whole Bilvashatak or can chant only this verse. Now take that Bilva leaf and put it on head, touch it on eyes and take it with you for the day. Put it in your pocket of shirt and take it with you.
This single leaf will make your whole day "Peacefull and energatic", this is true ritual. This leaf has that power.
Bilva tree is a tree so it can plant itself like any other tree anywhere. Wind can transfer this tree's seed to somewhere and it can grow anywhere by itself. No need to fear to have it in home garden.
No Hindu scriptures states any restriction in Bilva tree. Priests may have told you because they have fear that this tree's energy is more. But you can have confidence in your self, and can ignore them.
It is in your garden , so it will not be publicly available, if it would be in temple then more people can use it, so priests may have some good intention. After all they are priests so they must have some good intention. But personally I will tell you not to fear.
In Hinduism the Bilva tree is sacred.
It can be planted anywhere. Bilva leaves and fruits have very high medicinal value especially to cure stomach related problems. However, while planting Bilva tree it may be kept in mind that there is danger from falling fruits which are very hard and heavy and can cause injury.
Source: this link, which has a detailed explanation.
In any Purana nobody mentioned about where to grow trees. Growing Bilva Vriksha or nagavalli vrikasha, arjuna vriksha like many sacred trees is very good source of positive energy. Without any doubt in mind you just let it grow in your house. But remember they should not be in your north east side of your home.
Bilva gtree is the tree of Lakshmi. It is stated in Sri Sukta: "Aditya varne tapasodi jaatho vanaspathihi tha vriksho the bilvaha; Thasya phalani thapasanuthanthu mayaantha rayaantha bhagya lakshmihi"
This is why it is so beloved to Shankara, because the bilva tree emenated from the tapas of Maha Lakshmi. It is indeed a very auspicious tree to have in the home and will banish all signs of poverty.